Methods for Producing Corn Plants with Northern Leaf Blight Resistance and Compositions Thereof

ABSTRACT

The present disclosure is in the field of plant breeding and disease resistance. The disclosure provides methods for breeding corn plants having northern leaf blight (NLB) resistance using marker-assisted selection. The disclosure further provides corn germplasm resistant to NLB. The disclosure also provides markers associated with NLB resistance loci for introgressing these loci into elite germplasm in a breeding program, thus producing novel NLB resistant germplasm.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.16/877,649, filed May 19, 2020, which is a divisional of U.S.application Ser. No. 15/382,229, filed Dec. 16, 2016 (now U.S. Pat. No.10,694,693, issued Jun. 30, 2020), which claims the benefit and priorityof U.S. Provisional Application No. 62/269,635 filed Dec. 18, 2015,which are incorporated by reference in their entireties.

FIELD

The present disclosure relates to the field of agriculturalbiotechnology. More specifically, this disclosure relates to methods forproducing corn plants, seeds, or cells with improved northern leafblight resistance.

INCORPORATION OF SEQUENCE LISTING

A sequence listing contained in the file named P34361US03_SEQ.txt, whichis 217,339 bytes (measure in MS-Windows®) and created on Nov. 29, 2021,comprising 630 nucleotide sequences, is filed electronically herewithand incorporated by reference in its entirety.

BACKGROUND

Corn (Zea mays L.) is one of the most important commercial crops in theworld. Like many commercial crops, corn is subjected to numerouspotentially detrimental environmental conditions (e.g., moistureavailability, temperature stresses, soil conditions, pests, disease)that can reduce, or entirely eliminate, crop yield. Crop disease aloneaccounted for the loss of more than 1.3 billion bushels of corn in theUnited States and Ontario, Canada in 2012. See Mueller, Corn DiseaseLoss Estimates from the United States and Ontario, Canada—2012. PurdueExtension Publication BP-96-12-W (2014).

Northern leaf blight (NLB) is a crop disease caused by the fungalpathogen Exserohilum turcicum (also referred to as Helminthosporiumturcicum or Setosphaeria turcica in some literature). NLB can infectcorn in tropical and temperate climates. Infected corn plants canexhibit a range of symptoms from cigar-shaped lesions on lower leaves tocomplete destruction of multiple leaves. Corn infected with NLB is alsohighly susceptible to stem rot and root rot caused by secondaryinfections. NLB is particularly problematic in tropical highlands, whereenvironmental conditions favor disease development. However, NLBinfection can cause yield losses of 30%-50% in temperate environments,including the United States and Europe.

E. turcicum overwinters as mycelia and conidia on corn plant parts lefton the soil surface. The conidia are transformed into spores, and duringwarm, wet weather, new conidia are produced and carried by wind or rainonto the lower leaves of corn plants. Infection requires the presence ofwater on the leaf surface for at least 6 hours and a temperature ofbetween 65° F. and 80° F. If infection occurs, lesions develop within 12days and produce new conidia which can spread the infection toadditional leaves and plants. NLB management strategies include croprotation, destruction of over-wintering corn plant parts, and fungicideapplication. However, fungicide application alone is not an efficientmechanism of control, especially in Brazil.

There is a need in corn breeding to identify corn germplasm thatprovides resistance to NLB infection. There is also a need to developpolymorphic markers for monitoring and introgressing NLB resistancealleles, and further develop agronomically elite corn lines comprisingNLB resistance for enhancing plant productivity.

SUMMARY

The present disclosure identifies genetic loci conferring NLB resistancein corn, and provides molecular markers linked to these resistance loci.This disclosure further provides methods for introgressing resistancealleles of genetic loci conferring NLB resistance into plant varietiespreviously lacking such alleles, thereby providing plants with NLBresistance. The genetic loci, markers, and methods provided hereintherefore allow for production of new varieties with enhanced NLBresistance.

In one aspect, this disclosure provides a method of creating apopulation of corn plants, seeds, or cells comprising genotyping a firstpopulation of corn plants, seeds, or cells at one or more marker lociassociated with and within about 10 cM of one or more NLB resistancequantitative trait loci (QTLs) selected from the group consisting of NLBresistance QTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01,NLB_6.01, NLB_7.01, and NLB_9.01; selecting from the first populationone or more corn plants, seeds, or cells comprising one or more NLBresistance alleles of the one or more marker loci; and producing fromthe selected one or more corn plants, seeds, or cells a secondpopulation of corn plants, seeds, or cells comprising the one or moreNLB QTLs.

In one aspect, this disclosure provides a method of introgressing an NLBresistance QTL comprising crossing a first corn plant comprising an NLBresistance QTL with a second corn plant of a different genotype toproduce one or more progeny plants or seeds; and selecting a progenyplant or seed comprising an NLB resistance allele of a polymorphic locuslinked to the NLB resistance QTL, where the polymorphic locus is in achromosomal segment flanked by: any two of marker loci SEQ ID NOs: 1 to18, any two of marker loci SEQ ID NOs: 19 to 31, any two of marker lociSEQ ID NOs: 32 to 52 and 471-475, any two of marker loci SEQ ID NOs: 53to 65 and 446 to 468, any two of marker loci SEQ ID NOs: 66 to 84, anytwo of marker loci SEQ ID NOs: 85 to 89, marker loci SEQ ID NOs: 469 and470, or any two of marker loci SEQ ID NOs: 476-482.

In one aspect, this disclosure provides an NLB resistant corn plant,seed, or cell comprising a combination of two or more, three or more,four or more, five or more, six or more, or seven or more introgressedNLB resistance QTLs selected from the group consisting of NLB resistanceQTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01,NLB_7.01, and NLB_9.01.

In one aspect, this disclosure provides a method for selecting a cornplant, seed, or cell comprising isolating nucleic acids from a cornplant, seed, or cell; analyzing the nucleic acids to detect apolymorphic marker associated with and within 10 cM of an NLB resistanceQTL selected from the group consisting of NLB resistance QTLs NLB_2.01,NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, andNLB_9.01; and selecting a corn plant, seed, or cell comprising the NLBresistance QTL.

In one aspect, this disclosure provides a method comprising providing aset of corn seeds comprising one or more, two or more, three or more,four or more, five or more, six or more, or seven or more NLB resistanceQTLs selected from the group consisting of NLB resistance QTLs NLB_2.01,NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, andNLB_9.01, to a person desirous of planting said set of corn seeds in afield plot.

In one aspect, this disclosure provides a method of growing a populationof corn plants in a field plot, said method comprising planting apopulation of corn seeds comprising one or more, two or more, three ormore, four or more, five or more, six or more, or seven or moreintrogressed NLB resistance QTLs selected from the group consisting ofNLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01,NLB_6.01, NLB_7.01, and NLB_9.01 in said field plot.

BRIEF DESCRIPTION OF THE SEQUENCES

SEQ ID NOs: 1-89 and 446-482 list sequences of exemplary SNP marker lociassociated with an NLB resistance QTL. Example resistant and susceptiblealleles of these marker loci are listed in Table 5. SEQ ID NOs: 90-445and 483-630 list the sequences of exemplary primers and probes which canbe used to detect the SNP marker loci of SEQ ID NOs: 1-89 and 446-482.

DETAILED DESCRIPTION

Unless defined otherwise herein, terms are to be understood according toconventional usage by those of ordinary skill in the relevant art.Examples of resources describing many of the terms related to molecularbiology used herein can be found in Alberts et al., Molecular Biology ofThe Cell, 5^(th) Edition, Garland Science Publishing, Inc.: New York,2007; Rieger et al., Glossary of Genetics: Classical and Molecular, 5thedition, Springer-Verlag: New York, 1991; King et al, A Dictionary ofGenetics, 6th ed., Oxford University Press: New York, 2002; and Lewin,Genes IX, Oxford University Press: New York, 2007. The nomenclature forDNA bases as set forth at 37 C.F.R. § 1.822 is used.

As used herein, terms in the singular and the singular forms “a,” “an,”and “the,” for example, include plural referents unless the contentclearly dictates otherwise. Thus, for example, reference to “plant,”“the plant,” or “a plant” also includes a plurality of plants; also,depending on the context, use of the term “plant” can also includegenetically similar or identical progeny of that plant; use of the term“a nucleic acid” optionally includes, as a practical matter, many copiesof that nucleic acid molecule; similarly, the term “probe” optionally(and typically) encompasses many similar or identical probe molecules.

As used herein, “plant” refers to a whole plant and/or progeny of thesame. A progeny plant can be from any filial generation, e.g., F₁, F₂,F₃, F₄, F₅, F₆, F₇, etc. A “plant part” refers to any part of a plant,comprising a cell or tissue culture derived from a plant, plantcomponents or organs (e.g., leaves, stems, roots, etc.), plant tissues,seeds, and plant cells. A plant cell is a biological cell of a plant,taken from a plant or derived through culture from a cell taken from aplant.

As used herein, a “corn plant” or “maize plant” refers to a plant ofspecies Zea mays L and includes all plant varieties that can be bredwith corn, including wild maize species.

As used herein, “germplasm” refers to living sources of geneticmaterial. The germplasm can be part of an organism or cell, or can beseparate from the organism or cell. In general, germplasm providesgenetic material with a specific molecular makeup that provides aphysical foundation for some or all of the hereditary qualities of anorganism or cell culture. As used herein, germplasm includes cells,seed, or tissues from which new plants can be grown, or plant parts,such as leaves, stems, pollen, or cells that can be cultured into awhole plant.

As used herein, the phrase “associated with” or “linked to” refers to arecognizable and/or assayable relationship between two entities. Forexample, the phrase “associated with NLB resistance” refers to a trait,locus, gene, allele, marker, phenotype, etc., or the expression thereof,the presence or absence of which can influence an extent, degree, and/orrate at which a plant or a part of interest thereof that has an NLBresistance trait. As such, a marker is “associated with” a trait when itis linked to it and when the presence of the marker is an indicator ofwhether and/or to what extent the desired trait or trait form will occurin a plant/germplasm comprising the marker. Similarly, a marker is“associated with” an allele when it is linked to it and when thepresence of the marker is an indicator of whether the allele is presentin a plant/germplasm comprising the marker. For example, “a markerassociated with a resistance allele” refers to a marker whose presenceor absence can be used to predict whether and to what extent a plantwill display an NLB resistance phenotype.

As used herein, a “centimorgan” (cM) is a unit of measure ofrecombination frequency and genetic distance between two loci. One cM isequal to a 1% chance that a marker at one genetic locus will beseparated from a marker at a second locus due to crossing over in asingle generation.

As used herein, “closely linked” means that the marker or locus iswithin about 20 cM, 15 cM, 10 cM, 5 cM, 4 cM, 3 cM, 2 cM, 1 cM, 0.5 cM,or less than 0.5 cM of another marker or locus. For example, 20 cM meansthat recombination occurs between the marker and the locus with afrequency of equal to or less than about 20%.

As used herein, “locus” is a chromosome region or chromosomal regionwhere a polymorphic nucleic acid, trait determinant, gene, or marker islocated. A locus can represent a single nucleotide, a few nucleotides ora large number of nucleotides in a genomic region. The loci of thisdisclosure comprise one or more polymorphisms in a population (e.g.,alternative alleles are present in some individuals).

As used herein, “allele” refers to an alternative nucleic acid sequenceat a particular locus. The length of an allele can be as small as onenucleotide base. For example, a first allele can occur on onechromosome, while a second allele occurs on a second homologouschromosome, e.g., as occurs for different chromosomes of a heterozygousindividual, or between different homozygous or heterozygous individualsin a population.

As used herein, “crossed,” “cross,” or “crossing” means to produceprogeny via fertilization (e.g., cells, seeds, or plants) and includescrosses between plants (sexual) and self-fertilization (selfing).

As used herein, “backcross” and “backcrossing” refer to the processwhereby a progeny plant is repeatedly crossed back to one of itsparents. In a backcrossing scheme, the “donor” parent refers to theparental plant with the desired gene or locus to be introgressed. The“recipient” parent (used one or more times) or “recurrent” parent (usedtwo or more times) refers to the parental plant into which the gene orlocus is being introgressed. For example, see Ragot et al.,Marker-assisted Backcrossing: A Practical Example, in Techniques EtUtilisations Des Marqueurs Moleculaires Les Colloques, 72:45-56 (1995);and Openshaw et al., Marker-assisted Selection in Backcross Breeding, inProceedings Of The Symposium “Analysis Of Molecular Marker Data,” pp.41-43 (1994). The initial cross gives rise to the F₁ generation. Theterm “BC1” refers to the second use of the recurrent parent, “BC2”refers to the third use of the recurrent parent, and so on. In anaspect, a backcross is performed repeatedly, with a progeny individualof each successive backcross generation being itself backcrossed to thesame parental genotype.

As used herein, “agronomically elite background” means any line that hasresulted from breeding and selection for superior agronomic performance.Similarly, an “elite germplasm” or elite strain of germplasm is anagronomically superior germplasm. Numerous elite lines are available andknown to those of skill in the art of corn breeding.

As used herein, “genotype” is the genetic constitution of an individual(or group of individuals) at one or more genetic loci, as contrastedwith the observable trait (phenotype). Genotype is defined by theallele(s) of one or more known loci that the individual has inheritedfrom its parents. The term genotype can be used to refer to anindividual's genetic constitution at a single locus, at multiple loci,or, more generally, the term genotype can be used to refer to anindividual's genetic make-up for all the genes in its genome. The term“genotype” can also refer to determining the genetic constitution of anindividual (or group of individuals) at one or more genetic loci.

As used herein, a “haplotype” is the genotype of an individual at aplurality of genetic loci. Typically, the genetic loci described by ahaplotype are physically and genetically linked, e.g., in the samechromosome interval. A haplotype can also refer to a combination of SNPalleles located within a single gene.

As used herein, “marker assay” means a method for detecting apolymorphism at a particular locus using a particular method, e.g.measurement of at least one phenotype (such as seed color, flower color,or other visually detectable traits), restriction fragment lengthpolymorphism (RFLP), single base extension, electrophoresis, sequencealignment, allelic specific oligonucleotide hybridization (ASO), randomamplified polymorphic DNA (RAPD), microarray-based technologies, andnucleic acid sequencing technologies, etc.

As used herein, “marker assisted selection” (MAS) is a process by whichphenotypes are selected based on marker genotypes. “Marker assistedselection breeding” refers to the process of selecting a desired traitor traits in a plant or plants by detecting one or more nucleic acidsfrom the plant, where the nucleic acid is linked to the desired trait,and then selecting the plant or germplasm possessing those one or morenucleic acids.

As used herein, “polymorphism” means the presence of one or morevariations in a population. A polymorphism can manifest as a variationin the nucleotide sequence of a nucleic acid or as a variation in theamino acid sequence of a protein. Polymorphisms include the presence ofone or more variations of a nucleic acid sequence or nucleic acidfeature at one or more loci in a population of one or more individuals.The variation can comprise, but is not limited to, one or morenucleotide base changes, the insertion of one or more nucleotides or thedeletion of one or more nucleotides. A polymorphism can arise fromrandom processes in nucleic acid replication, through mutagenesis, as aresult of mobile genomic elements, from copy number variation and duringthe process of meiosis, such as unequal crossing over, genomeduplication, and chromosome breaks and fusions. The variation can becommonly found or can exist at low frequency within a population, theformer having greater utility in general plant breeding and the lattercan be associated with rare but important phenotypic variation. Usefulpolymorphisms can include a single nucleotide polymorphisms (SNP), aninsertion or deletion in DNA sequence (indel), a simple sequence repeatsof DNA sequence (SSR), a restriction fragment length polymorphism(RFLP), and a tag SNP. A genetic marker, a gene, a DNA-derived sequence,a RNA-derived sequence, a promoter, a 5′ untranslated region of a gene,a 3′ untranslated region of a gene, microRNA, small interfering RNA, atolerance locus, a satellite marker, a transgene, mRNA, double-strandedRNA, a transcriptional profile, and a methylation pattern can alsocomprise a polymorphism. In addition, the presence, absence, orvariation in copy number of the preceding can comprise a polymorphism.

As used herein, “SNP” or “single nucleotide polymorphism” means asequence variation that occurs when a single nucleotide (A, T, C, or G)in the genome sequence is altered or variable. “SNP markers” exist whenSNPs are mapped to sites on the genome.

As used herein, “marker,” “molecular marker,” or “marker locus” is aterm used to denote a nucleic acid or amino acid sequence that issufficiently unique to characterize a specific locus on the genome. Anydetectable polymorphic trait can be used as a marker so long as it isinherited differentially and exhibits linkage disequilibrium with aphenotypic trait of interest. A number of markers and integrated geneticmaps have been developed for corn (e.g., the UMC 98 map, the NestedAssociation Mapping (NAM) map, the Intermated B73/Mol7 (IBM2) Neighbors2008 genetic map, and the LHRF Gnp2004 map. Seemaizegdb.org/data_center/map for more). All markers are used to define aspecific locus in corn genomes. Large numbers of these markers have beenmapped. See maizegdb.org/data_center/marker. Each marker is therefore anindicator of a specific segment of DNA, having a unique nucleotidesequence. The map positions provide a measure of the relative positionsof particular markers with respect to one another. When a trait isstated to be linked to a given marker it will be understood that theactual DNA segment whose sequence affects the trait generallyco-segregates with the marker. More precise and definite localization ofa trait can be obtained if markers are identified on both sides of thetrait. By measuring the appearance of the marker(s) in progeny ofcrosses, the existence of the trait can be detected by relatively simplemolecular tests without actually evaluating the appearance of the traititself, which can be difficult and time-consuming because the actualevaluation of the trait requires growing plants to a stage and/or underenvironmental conditions where the trait can be expressed. Molecularmarkers have been widely used to determine genetic composition in corn.In an aspect, markers used herein exhibit LOD scores of 2 or greater, 3or greater, 4 or greater, 5 or greater, 6 or greater, 7 or greater, 8 orgreater, or 9 or greater with an associated trait of interest (e.g., NLBresistance), measuring using a method known in the art such as QgeneVersion 2.23 (1996) and default parameters. Without being limiting,examples of molecular markers and molecular marker systems include SNPs,indels, RFLPs, SSRs, restriction site-associated DNA (RAD), diversityarray technology (DArT), and genotyping by sequencing (GBS).

As used herein, “linkage disequilibrium” (LD) refers to a non-randomsegregation of genetic loci or traits (or both). In either case, linkagedisequilibrium implies that the relevant loci are within sufficientphysical proximity along a length of a chromosome so that they segregatetogether with greater than random (i.e., non-random) frequency (in thecase of co-segregating traits, the loci that underlie the traits are insufficient proximity to each other). Linked loci co-segregate more than50% of the time, e.g., from about 51% to about 100% of the time. Linkagedisequilibrium can be measured using any one of the methods provided inHedrick, Gametic disequilibrium measures: proceed with caution.Genetics, 117:331-41(1987). The term “physically linked” is sometimesused to indicate that two loci, e.g., two marker loci, are physicallypresent on the same chromosome. Advantageously, the two linked loci arelocated in close proximity such that recombination between homologouschromosome pairs does not occur between the two loci during meiosis withhigh frequency, e.g., such that linked loci co-segregate at least about90% of the time, e.g., 91%, 92%, 93%, 94%, 95%, 96%, 97%, 98%, 99%,99.5%, 99.75%, or more of the time.

As used herein, a “genetic map” is the relationship of genetic linkageamong loci on one or more chromosomes (or linkage groups) within a givenspecies, generally depicted in a diagrammatic or tabular form. Geneticmapping is the process of defining the linkage relationships of locithrough the use of genetic markers, populations segregating for themarkers, and standard genetic principles of recombination frequency. Agenetic map location is a location on a genetic map relative tosurrounding genetic markers on the same linkage group where a specifiedmarker can be found within a given species. In contrast, a “physicalmap” of the genome refers to absolute distances (for example, measuredin base pairs or isolated and overlapping contiguous genetic fragments,e.g., contigs). In general, the closer two markers or genomic loci areon the genetic map, the closer they lie to one another on the physicalmap. A physical map of the genome does not take into account the geneticbehavior (e.g., recombination frequencies) between different points onthe physical map. A lack of precise proportionality between geneticdistances and physical distances can exist due to the fact that thelikelihood of genetic recombination is not uniform throughout thegenome; some chromosome regions are cross-over “hot spots,” while otherregions demonstrate only rare recombination events, if any. Geneticmapping variability can also be observed between different populationsof the same crop species. In spite of this variability in the geneticmap that can occur between populations, genetic map and markerinformation derived from one population generally remains useful acrossmultiple populations in identification of plants with desired traits,counter-selection of plants with undesirable traits and in MAS breeding.As one of skill in the art will recognize, recombination frequencies(and as a result, genetic map positions) in any particular populationare not static. The genetic distances separating two markers (or amarker and a QTL) can vary depending on how the map positions aredetermined. For example, variables such as the parental mappingpopulations used, the software used in the marker mapping or QTLmapping, and the parameters input by the user of the mapping softwarecan contribute to the QTL marker genetic map relationships. However, itis not intended that this disclosure be limited to any particularmapping populations, use of any particular software, or any particularset of software parameters to determine linkage of a particular markeror haplotypes with a desired phenotype. It is well within the ability ofone of ordinary skill in the art to extrapolate the novel featuresdescribed herein to any gene pool or population of interest, and usingany particular software and software parameters. Indeed, observationsregarding genetic markers and haplotypes in populations in addition tothose described herein are readily made using the teaching of thepresent disclosure.

As used herein, “selecting” or “selection” in the context ofmarker-assisted selection or breeding refer to the act of picking orchoosing desired individuals, normally from a population, based oncertain pre-determined criteria.

As used herein, “primer” refers to an oligonucleotide (synthetic oroccurring naturally), which is capable of acting as a point ofinitiation of nucleic acid synthesis or replication along acomplementary strand when placed under conditions in which synthesis ofa complementary strand is catalyzed by a polymerase. Typically, primersare about 10 to 30 nucleotides in length, but longer or shortersequences can be employed. Primers can be provided in double-strandedform, though the single-stranded form is more typically used. A primercan further contain a detectable label (e.g., a 5′ end label).

As used herein, “probe” refers to an oligonucleotide (synthetic oroccurring naturally) that is complementary (though not necessarily fullycomplementary) to a polynucleotide of interest and forms a duplexstructure by hybridization with at least one strand of thepolynucleotide of interest. Typically, probes are oligonucleotides from10 to 50 nucleotides in length, but longer or shorter sequences can beemployed. A probe can further contain a detectable label.

As used herein, a “population of plants” or a “population of seeds”means a set comprising any number, at least two, of individuals,objects, or data from which samples are taken for evaluation. Mostcommonly, the terms relate to a breeding population of plants from whichmembers are selected and crossed to produce progeny in a breedingprogram. A population of plants can include the progeny of a singlebreeding cross or a plurality of breeding crosses, and can be eitheractual plants or plant derived material, or in silico representations ofthe plants or seeds. The population members need not be identical to thepopulation members selected for use in subsequent cycles of analyses orthose ultimately selected to obtain final progeny plants or seeds.Often, a population of plants or seeds is derived from a singlebiparental cross, but can also derive from two or more crosses betweenthe same or different parents. Although a population of plants or seedscan comprise any number of individuals, those of skill in the art willrecognize that plant breeders commonly use population sizes ranging fromone or two hundred individuals to several thousand, and that the highestperforming 5% to 20% of a population is what is commonly selected to beused in subsequent crosses in order to improve the performance ofsubsequent generations of the population.

As used herein, “cultivar” and “variety” are used synonymously and meana group of plants within a species (e.g., Z. mays L.) that share certaingenetic traits that separate them from other possible varieties withinthat species. Corn cultivars can be inbreds or hybrids, thoughcommercial corn cultivars are mostly hybrids to take advantage of hybridvigor. Individuals within a corn hybrid cultivar are homogeneous, nearlygenetically identical, with most loci in the heterozygous state.

As used herein, the term “inbred” means a line that has been bred forgenetic homogeneity.

As used herein, the term “hybrid” means a progeny of mating between atleast two genetically dissimilar parents. Without limitation, examplesof mating schemes include single crosses, modified single cross, doublemodified single cross, three-way cross, modified three-way cross, anddouble cross wherein at least one parent in a modified cross is theprogeny of a cross between sister lines.

As used herein, “introgression” refers to the transmission of a desiredallele of a genetic locus from one genetic background to another.

As used herein, the term “chromosome interval” or “chromosomal interval”designates a contiguous linear span of genomic DNA that resides on asingle chromosome.

As used herein, “flanked by,” when used to describe a chromosomalinterval, refers to two loci physically surrounding the chromosomalinterval, with one locus on each side of the chromosomal interval. Asreferenced herein, a chromosomal interval flanked by two marker lociincludes the two marker loci.

As used herein, a “resistant allele” or “resistance allele” is an alleleat a particular locus that confers, or contributes to, NLB resistance,or alternatively, is an allele that allows the identification of plantsthat comprise NLB resistance. A resistant allele of a marker is a markerallele that segregates with NLB resistance, or alternatively, segregateswith NLB susceptibility, therefore providing the benefit of identifyingplants having NLB susceptibility. A resistant allelic form of achromosome interval is a chromosome interval that includes a nucleotidesequence that contributes to NLB resistance at one or more genetic lociphysically located in the chromosome interval.

As used herein, “genetic element” or “gene” refers to a heritablesequence of DNA, e.g., a genomic sequence, with functional significance.The term “gene” can also be used to refer to, e.g., a cDNA and/or anmRNA encoded by a genomic sequence, as well as to that genomic sequence.

As used herein, the terms “phenotype,” or “phenotypic trait,” or “trait”refers to one or more detectable characteristics of a cell or organismwhich can be influenced by genotype. The phenotype can be observable tothe naked eye, or by any other means of evaluation known in the art,e.g., microscopy, biochemical analysis, genomic analysis, an assay for aparticular disease tolerance, etc. In some cases, a phenotype isdirectly controlled by a single gene or genetic locus, e.g., a “singlegene trait.” In other cases, a phenotype is the result of several genes.

As used herein, “resistance” and “enhanced resistance” are usedinterchangeably herein and refer to any type of increase in resistance,or any type of decrease in susceptibility. A plant or plant varietyexhibiting resistance need not possess absolute or complete resistance.Instead, a plant or plant variety with “enhanced resistance” will have alevel of resistance which is higher than that of a comparablesusceptible plant or variety. The level of NLB resistance can bedetermined based on disease ratings as determined in Example 1. Briefly,resistance to NLB infection of corn plants is scored using an NLBresistance scale, wherein NLB resistance is measured by rating thepercentage of leaf area infected on a scale of 1 to 9. An NLB resistancescale comprises ratings of: 1 (highly resistant; 0% of leaf areainfected, no visible lesions), 2 (highly resistant; less than 1% leafarea infected, few lesions dispersed through lower leaves), 3(resistant; 1% to less than 20% leaf area infected), 4 (resistant; 20%to less than 40% leaf area infected), 5 (mildly resistant; 40% to lessthan 50% leaf area infected, lesions reaching ear leaf with sparselesions in leaves above the ear), 6 (mildly susceptible; 50% to lessthan 60% leaf area infected, lesions reaching the leaves above theears), 7 (susceptible; 60% to less than 75% leaf area infected), 8(susceptible; 75% to less than 90% leaf area infected), and 9(susceptible; greater than 90% of leaf area infected, with prematuredeath of the plant).

As used herein, “quantitative trait locus” (QTL) or “quantitative traitloci” (QTLs) refer to a genetic domain that effects a phenotype that canbe described in quantitative terms and can be assigned a “phenotypicvalue” which corresponds to a quantitative value for the phenotypictrait.

As used herein, “adjacent”, when used to describe a nucleic acidmolecule that hybridizes to DNA containing a polymorphism, refers to anucleic acid that hybridizes to DNA sequences that directly abut thepolymorphic nucleotide base position. For example, a nucleic acidmolecule that can be used in a single base extension assay is “adjacent”to the polymorphism.

As used herein, “northern leaf blight” or “NLB” refers to a plantdisease caused by the fungal pathogen Exserohilum turcicum, which isalso referred to as Helminthosporium turcicum or Setosphaeria turcica.

As used herein, “field plot” refers to a location that is suitable forgrowing corn. The location can be indoors (e.g., a greenhouse or agrowth chamber) or outdoors; irrigated or non-irrigated; in the groundor in a container that holds soil.

As used herein, a “planting season” is the length of time, typicallyabout 90-120 days, in which corn can be grown from seed to maturity. Oneskilled in the art would recognize that a “planting season” could besignificantly shorter or longer than about 90-120 days depending on thecorn variety being grown and environmental conditions.

As used herein, “transgenic” means a plant or seed whose genome has beenaltered by the stable integration of recombinant DNA. A transgenic lineincludes a plant regenerated from an originally-transformed plant celland progeny transgenic plants from later generations or crosses of atransformed plant.

As used herein, “haploid” means a line that has had its normalchromosome complement reduced by half, typically by pollinating an earwith pollen from a haploid inducing line. In corn, haploid refers to anindividual plant or seed that has a haploid chromosome complement wheren=10, instead of the normal diploid chromosome complement where 2n=20. A“doubled haploid” refers to a haploid line (n=10) that has been induced,typically via chemical means, to double its chromosome complement andreturn to a diploid state (2n=20) that is homozygous at all loci withinthe genome.

As used herein, “yield penalty” refers to a reduction of seed yield in aline correlated with or caused by the presence of an NLB resistanceallele or NLB resistance QTL as compared to a line that does not containthat NLB resistance allele or NLB resistance QTL.

As used herein, “seed yield” can refer to a measure of crop productionsuch as test weight, seed number per plant, seed weight, seed number perunit area (i.e. seeds, or weight of seeds, per acre), bushels per acre,tons per acre, kilograms per hectare, or quintals per hectare.

Northern leaf blight is a plant disease caused by the fungal pathogenExserohilum turcicum (also referred to as Helminthosporium turcicum orSetosphaeria turcica by some researchers). NLB afflicts corn intemperate and tropical regions worldwide. NLB is endemic to the UnitedStates. Yield losses of over 30% are reported in susceptible hybrids,and yield loss can reach 70% if the onset of NLB infection occurs 2-3weeks after silking. See Perkins and Pedersen, Disease development andyield losses associated with northern leaf blight on corn, PlantDisease, 71: 940-943 (1987); and Pataky, Relationships between yield ofsweet corn and northern leaf blight caused by Exserohilum turcicum,Phytopathology, 82: 370-375 (1992).

Corn plants in tropical regions are especially at risk to NLB infectiondue to environmental conditions that are conducive to NLB growth. E.turcicum thrives in humid environments with heavy dews, frequent rainshowers, and moderate temperatures. However, E. turcicum alsooverwinters in areas that see hard freezes as mycelia and conidia oncorn plant parts left on the soil surface and NLB is also a major corndisease in temperate regions. NLB conidia are transformed into restingspores during warm, wet weather in spring and early summer. New conidiaare then produced and carried by wind or rain onto the lower leaves ofyoung corn plants. Infection requires the presence of water on the leafsurface for 6-18 hours and a temperature of between 65° F. and 80° F. Ifinfection occurs, lesions develop within 12 days and produce new conidiawhich can spread the infection to additional leaves and plants via newspores carried by wind or rain. NLB lesions can begin producing sporesin as little as 7 days under ideal conditions. Generally, NLB infectionsbegin on lower leaves and progress upwards to younger leaves. However,during high spore loads infections can begin at the top of the plant,including the tassel and flag leaf.

The first sign of NLB infection is an elliptical, or cigar-shaped,gray-green lesion. Lesions typically, but not always, occur on lowerleaves before upper leaves. As lesions enlarge they can reach over 6inches in length and turn a pale gray to brown in color. NLB lesions arenot restricted by leaf veins, and the entire leaf can be covered by oneor a few lesions in an advanced infection as individual lesions grow andmerge. Leaves from highly susceptible plants often appear gray orburned, with little or no healthy, green, photosynthetic tissueremaining. The reduction in tissue capable of photosynthesis leads to alack of carbohydrates needed for grain fill, which can reduce seedyield. During moist conditions lesions, especially on a lower leafsurface, can produce numerous dark gray spores. Plants infected with NLBare also susceptible to secondary infections from fungi, bacteria,and/or viruses that can cause stem rot and/or root rot.

Several fungicides, including picoxystrobin, cyproconazole,tetraconazole, pyraclostrobin, metconazole, azoxystrobin, propiconazole,prothioconazole, trifloxystrobin, and combinations thereof are used totreat NLB. However, reliance on chemical agents to reduce NLB incidenceis unreliable because NLB can develop resistance to the chemical agents.

Four NLB resistance loci conferring incomplete, race-specific, NLBresistance have been reported in corn: Ht1, Ht2, Ht3, and Htn1.Resistance conferred by these loci appears dependent on environmentalconditions (e.g., light, temperature), and the loci tend to conferdelayed leaf lesion development or delayed sporulation rather thancomplete disease resistance.

Ht1 maps to the long arm of chromosome 1. See Bentolila et al.,Identification of an RFLP marker tightly linked to the Ht1 gene inmaize. Theoretical and Applied Genetics. 82: 393-398 (1991). Ht2 maps tothe long arm of chromosome 8, and Htn1 maps approximately 10centimorgans distal to Ht2 on chromosome 8. See Zaitlin et al., Linkageof a second gene for NCLB resistance to molecular markers in maize.Maize Genetics Cooperative Newsletter. 66: 69-70 (1992); Simcox andBennetzen, The use of molecular markers to study Setosphaeria turcicaresistance in maize. Phytopathology. 83: 1326-1330 (1993); Yin et al.,Fine mapping of the Ht2 (Helminthosporium turcicum resistance 2) gene inmaize. Chinese Science Bulletin. 48: 165-169 (2003); and Chung et al.,Characterization and fine-mapping of a resistance locus for northernleaf blight in maize bin 8.06. Theoretical and Applied Genetics. 121:205-227 (2010). Ht3 maps to chromosome 7. See Van Staden et al., SCARmarkers for the Ht1, Ht2, Ht3, and Htn1 resistance genes in maize. MaizeGenetics Conference Abstract. 43: P134 (2001).

A corn plant, seed, or cell provided herein possesses one or more NLBresistance QTLs and/or one or more NLB resistance alleles that conferenhanced resistance to NLB compared to a corn plant, seed, or cell thatlacks the one or more NLB resistance QTLs and/or one or more NLBresistance alleles. Further, a corn plant, seed, or cell provided hereinprovided herein does not suffer a yield penalty when grown in theabsence of NLB spores, conidia, and/or mycelia.

In an aspect, a corn plant, seed, or cell provided herein is a Zea maysL. corn plant, seed, or cell. In another aspect, a corn plant, seed, orcell provided herein is a Zea mays ssp. mays corn plant, seed, or cell.In yet another aspect, a corn plant or seed provided herein is adomesticated line, cultivar, or variety of corn plant or seed. Inanother aspect, a corn plant, seed, or cell provided herein is a sweetcorn plant, sweet corn seed, or sweet corn cell.

In an aspect, this disclosure provides quantitative trait loci (QTLs)that exhibit significant co-segregation with NLB resistance. The QTLs ofthis disclosure can be tracked during plant breeding or introgressedinto a desired genetic background in order to provide plants exhibitingenhanced NLB resistance and one or more other beneficial traits. As anexample, this disclosure identifies QTL intervals that are associatedwith NLB resistance in corn varieties CV114258, CV115214, CV099829,CV102084, CV095508, CV103141, CV105893, CV595358, CV593417, CV117407,CV592505, and CV592420.

In an aspect, this disclosure provides molecular markers closely linkedto one or more NLB resistance QTLs and methods of using these markersfor detection of and selection for NLB resistance. An aspect of thisdisclosure includes specific markers and their resistance alleles,chromosome intervals comprising the markers, and methods of detectingmarkers genetically linked to NLB resistance to identify plant lineswith enhanced NLB resistance. For example, one aspect of this disclosureprovides a chromosome interval associated with NLB resistance which isflanked by any two of marker loci SEQ ID NOs: 12 to 15. Another exampleof this disclosure provides a chromosome interval associated with NLBresistance, where the interval is flanked by any two of marker loci SEQID NOs: 22 to 25. Another example of this disclosure provides achromosome interval associated with NLB resistance which is flanked byany two of marker loci SEQ ID NOs: 37 to 42 and 474. Another example ofthis disclosure provides a chromosome interval associated with NLBresistance which is flanked by any two of marker loci SEQ ID NOs: 44 to49. Another example of this disclosure provides a chromosome intervalassociated with NLB resistance which is flanked by any two of markerloci SEQ ID NOs: 57 to 62 and 458 to 466. Another example of thisdisclosure provides a chromosome interval associated with NLB resistancewhich is flanked by any two of marker loci SEQ ID NOs: 79 to 81. Anotherexample of this disclosure provides a chromosome interval associatedwith NLB resistance which is flanked by any two of marker loci SEQ IDNOs: 87 to 89 and 477 to 480. Another example of this disclosureprovides a chromosome interval associated with NLB resistance which isflanked by marker loci SEQ ID NOs: 469 and 470.

One aspect of this disclosure provides a chromosome interval associatedwith NLB resistance which is flanked by any two of marker loci SEQ IDNOs: 8 to 18. Another aspect of this disclosure provides a chromosomeinterval associated with NLB resistance, where the interval is flankedby any two of marker loci SEQ ID NOs: 21 to 29. Another aspect of thisdisclosure provides a chromosome interval associated with NLB resistancewhich is flanked by any two of marker loci SEQ ID NOs: 33 to 42, 473,and 474. Another aspect of this disclosure provides a chromosomeinterval associated with NLB resistance which is flanked by any two ofmarker loci SEQ ID NOs: 43 to 49 and 475. Another aspect of thisdisclosure provides a chromosome interval associated with NLB resistancewhich is flanked by any two of marker loci SEQ ID NOs: 57 to 64 and 458to 468. Another aspect of this disclosure provides a chromosome intervalassociated with NLB resistance which is flanked by any two of markerloci SEQ ID NOs: 74 to 82. Another aspect of this disclosure provides achromosome interval associated with NLB resistance which is flanked byany two of marker loci SEQ ID NOs: 86 to 89 and 476, 477, 479, and 480.Also provided herein are markers, e.g., SEQ ID NOs: 1-89 and 446-482,that are useful for tracking NLB resistant alleles and can be used inMAS breeding programs to produce plants with enhanced NLB resistance.

This disclosure further provides methods of using the markers identifiedherein to introgress loci associated with NLB resistance into NLBsusceptible plants. As an example, one skilled in the art can use thisdisclosure to create a novel corn plant, seed, or cell with NLBresistance by crossing a donor line comprising a QTL provided hereinwith any desired recipient line, with or without MAS.

In another aspect, this disclosure further provides methods forintrogressing multiple NLB resistance QTLs identified herein to generatean enhanced NLB resistant population of corn plants, seeds, or cells.

In an aspect, this disclosure provides a method of creating a populationof corn plants, seeds, or cells, where the method comprises the stepsof: (a) genotyping a first population of corn plants, seeds, or cells atone or more marker loci associated with one or more NLB resistance QTLsselected from the group consisting of NLB resistance QTLs NLB_2.01,NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, andNLB_9.01; (b) selecting from the first population one or more cornplants, seeds, or cells comprising one or more NLB resistance alleles ofthe one or more marker loci; and (c) producing from the selected one ormore corn plants, seeds, or cells a second population of corn plants,seeds, or cells comprising one or more NLB QTLs.

In an aspect, this disclosure provides a corn plant, seed, or cell asdescribed in any of paragraphs [00175] to [00183], where the corn seedfurther comprises one or more NLB resistance loci selected from thegroup consisting of Ht1, Ht2, Ht3, and Htn1. In another aspect, thisdisclosure provides a corn plant, seed, or cell as described in any ofparagraphs [00175] to [00183], where the corn seed further comprises twoor more NLB resistance loci selected from the group consisting of Ht1,Ht2, Ht2, and Htn1. In another aspect, this disclosure provides a cornplant, seed, or cell as described in any of paragraphs [00175] to[00183], where the corn seed further comprises three or more NLBresistance loci selected from the group consisting of Ht1, Ht2, Ht2, andHtn1. In another aspect, this disclosure provides a corn plant, seed, orcell as described in any of paragraphs [00175] to [00183], where thecorn seed further comprises NLB resistance loci Ht1, Ht2, Ht2, and Htn1.

In another aspect, this disclosure provides a corn plant, seed, or cellcomprising a first NLB resistance locus selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01 and a second NLBresistance locus Ht1. In another aspect, this disclosure provides a cornplant, seed, or cell comprising a first NLB resistance locus selectedfrom the group consisting of NLB resistance QTLs NLB_2.01, NLB_3.01,NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01 and asecond NLB resistance locus Ht2. In another aspect, this disclosureprovides a corn plant, seed, or cell comprising a first NLB resistancelocus selected from the group consisting of NLB resistance QTLsNLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01,and NLB_9.01 and a second NLB resistance locus Ht3. In another aspect,this disclosure provides a corn plant, seed, or cell comprising a firstNLB resistance locus selected from the group consisting of NLBresistance QTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01,NLB_6.01, NLB_7.01, and NLB_9.01 and a second NLB resistance locus Htn1.

In another aspect, this disclosure provides a corn plant, seed, or cellcomprising a first NLB resistance locus selected from the groupconsisting of NLB resistance QTLs NLB_4.01 and NLB_4.02 and a second NLBresistance locus selected from the group consisting of Ht1, Ht2, Ht3,and Htn1. In another aspect, this disclosure provides a corn plant,seed, or cell comprising a first NLB resistance locus selected from thegroup consisting of NLB resistance QTLs NLB_4.01 and NLB_4.02 and asecond NLB resistance locus Ht1. In another aspect, this disclosureprovides a corn plant, seed, or cell comprising a first NLB resistancelocus selected from the group consisting of NLB resistance QTLs NLB_4.01and NLB_4.02 and a second NLB resistance locus Ht2. In another aspect,this disclosure provides a corn plant, seed, or cell comprising a firstNLB resistance locus selected from the group consisting of NLBresistance QTLs NLB_4.01 and NLB_4.02 and a second NLB resistance locusHt3. In another aspect, this disclosure provides a corn plant, seed, orcell comprising a first NLB resistance locus selected from the groupconsisting of NLB resistance QTLs NLB_4.01 and NLB_4.02 and a second NLBresistance locus Htn1.

In an aspect, this disclosure provides a method of creating a populationof corn plants, seeds, or cells, which method comprising the steps of:(a) genotyping a first population of corn plants, the populationcomprising at least one allele associated with NLB resistance, whereinthe NLB resistance allele is associated with a marker selected from thegroup consisting of SEQ ID NOs: 1-89 and 446-482; (b) selecting from thefirst population one or more corn plants, seeds, or cells comprising theNLB resistance allele; and (c) producing from the selected corn plants,seeds, or cells a second population of corn plants, seeds, or cellscomprising the at least one NLB resistance allele.

In an aspect, this disclosure provides a method for introgressing aresistance allele of a locus conferring NLB resistance, which methodcomprising the steps of: (a) crossing a first corn plant with a secondcorn plant, wherein the first corn plant comprises the resistanceallele, wherein the NLB resistance allele is associated with a markerselected from the group consisting of SEQ ID NOs: 1-89 and 446-482; (b)genotyping a progeny corn plant or seed from the cross using a markerassociated with the resistance allele; and (c) selecting a progeny plantor seed comprising the resistance allele.

In an aspect, this disclosure provides a method for introgressing an NLBresistance QTL, which method comprising the steps of: (a) crossing afirst corn plant comprising an NLB resistance QTL selected from thegroup consisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01, with a second cornplant of a different genotype to produce one or more progeny plants orseeds; (b) assaying the one or more progeny plants or seeds at a markerlocus associated with the NLB resistance QTL; and (c) selecting aprogeny plant or seed comprising the NLB resistance QTL.

In an aspect, this disclosure provides a method for creating apopulation of corn plants, seeds, or cells with NLB resistance, whichmethod comprising the steps of: (a) concurrently detecting in a firstpopulation of corn plants, seeds, or cells the presence of a combinationof two or more, three or more, four or more, five or more, six or more,or seven or more introgressed NLB resistance loci selected from thegroup consisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01; (b) selecting fromthe first population one or more corn plants or seed comprising the oneor more, two or more, three or more, four or more, five or more, six ormore, or seven or more introgressed NLB resistance QTLs; and (c)producing a population of offspring from the selected one or more cornplants, seeds, or cells. In an aspect, a method comprises concurrentdetection of one or more molecular markers located in at least onechromosome interval flanked by any two of marker loci SEQ ID NOs: 1 to18, any two of marker loci SEQ ID NOs: 19 to 31, any two of marker lociSEQ ID NOs: 32 to 52 and 471 to 475, any two of marker loci SEQ ID NOs:53 to 65 and 446 to 468, any two of marker loci SEQ ID NOs: 66 to 84,any two of marker loci SEQ ID NOs: 85 to 89 and 476 to 482, or markerloci SEQ ID NOs: 469 and 470. In another aspect, a method comprisesconcurrent detection of one or more molecular markers located in atleast one chromosome interval flanked by any two of marker loci SEQ IDNOs: 12 to 15, any two of marker loci SEQ ID NOs: 22 to 25, any two ofmarker loci SEQ ID NOs: 37 to 42 and 474, any two of marker loci SEQ IDNOs: 44 to 49, any two of marker loci SEQ ID NOs: 57 to 62 and 458 to466, any two of marker loci SEQ ID NOs: 79 to 81, or any two of markerloci SEQ ID NOs: 87 to 89 and 477 to 480. In another aspect, a methodcomprises concurrent detection of one or more molecular markers locatedin at least one chromosome interval flanked by any two of marker lociSEQ ID NOs: 8 to 18, any two of marker loci SEQ ID NOs: 21 to 29, anytwo of marker loci SEQ ID NOs: 33 to 42, 473, and 474, any two of markerloci SEQ ID NOs: 43 to 49 and 475, any two of marker loci SEQ ID NOs: 57to 64 and 458 to 468, any two of marker loci SEQ ID NOs: 74 to 82, orany two of marker loci SEQ ID NOs: 86 to 89 and 476, 477, 479, and 480.

In an aspect, a method comprises concurrently detecting NLB resistanceQTLs NLB_4.01, and NLB_4.02. In another aspect, a method comprisesconcurrently detecting NLB resistance QTLs NLB_4.01 and NLB_4.02 and atleast one or more NLB resistance QTLs selected from the group consistingof NLB_2.01, NLB_3.01, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. Inanother aspect, a method comprises concurrently detecting NLB resistanceQTLs NLB_4.01 and NLB_4.02 and at least two or more NLB resistance QTLsselected from the group consisting of NLB_2.01, NLB_3.01, NLB_5.01,NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a method comprisesconcurrently detecting NLB resistance QTLs NLB_4.01 and NLB_4.02 and atleast three or more NLB resistance QTLs selected from the groupconsisting of NLB_2.01, NLB_3.01, NLB_5.01, NLB_6.01, NLB_7.01, andNLB_9.01. In another aspect, a method comprises concurrently detectingNLB resistance QTLs NLB_4.01 and NLB_4.02 and at least four or more NLBresistance QTLs selected from the group consisting of NLB_2.01,NLB_3.01, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect,a method comprises concurrently detecting NLB resistance QTLs NLB_4.01and NLB_4.02 and at least five or more NLB resistance QTLs selected fromthe group consisting of NLB_2.01, NLB_3.01, NLB_5.01, NLB_6.01,NLB_7.01, and NLB_9.01.

In another aspect, a method comprises concurrently detecting NLBresistance QTLs NLB_3.01, NLB_4.01, and NLB_4.02. In another aspect, amethod comprises concurrently detecting NLB resistance QTLs NLB_3.01,NLB_4.01, and NLB_4.02 and at least one or more NLB resistance QTLsselected from the group consisting of NLB_2.01, NLB_5.01, NLB_6.01,NLB_7.01, and NLB_9.01. In another aspect, a method comprisesconcurrently detecting NLB resistance QTLs NLB_3.01, NLB_4.01, andNLB_4.02 and at least two or more NLB resistance QTLs selected from thegroup consisting of NLB_2.01, NLB_5.01, NLB_6.01, NLB_7.01, andNLB_9.01. In another aspect, a method comprises concurrently detectingNLB resistance QTLs NLB_3.01, NLB_4.01, and NLB_4.02 and at least threeor more NLB resistance QTLs selected from the group consisting ofNLB_2.01, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect,a method comprises concurrently detecting NLB resistance QTLs NLB_3.01,NLB_4.01, and NLB_4.02 and at least four or more NLB resistance QTLsselected from the group consisting of NLB_2.01, NLB_5.01, NLB_6.01,NLB_7.01, and NLB_9.01.

In another aspect, a method comprises concurrently detecting NLBresistance QTLs NLB_3.01 and NLB_4.01. In another aspect, a methodcomprises concurrently detecting NLB resistance QTLs NLB_3.01 andNLB_4.01 and at least one or more NLB resistance QTLs selected from thegroup consisting of NLB_2.01, NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01,and NLB_9.01. In another aspect, a method comprises concurrentlydetecting NLB resistance QTLs NLB_3.01 and NLB_4.01 and at least two ormore NLB resistance QTLs selected from the group consisting of NLB_2.01,NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect,a method comprises concurrently detecting NLB resistance QTLs NLB_3.01and NLB_4.01 and at least three or more NLB resistance QTLs selectedfrom the group consisting of NLB_2.01, NLB_4.02, NLB_5.01, NLB_6.01,NLB_7.01, and NLB_9.01. In another aspect, a method comprisesconcurrently detecting NLB resistance QTLs NLB_3.01 and NLB_4.01 and atleast four or more NLB resistance QTLs selected from the groupconsisting of NLB_2.01, NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, andNLB_9.01. In another aspect, a method comprises concurrently detectingNLB resistance QTLs NLB_3.01 and NLB_4.01 and at least five or more NLBresistance QTLs selected from the group consisting of NLB_2.01,NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01.

In another aspect, a method comprises concurrently detecting NLBresistance QTLs NLB_3.01 and NLB_4.02. In another aspect, a methodcomprises concurrently detecting NLB resistance QTLs NLB_3.01 andNLB_4.02 and at least one or more NLB resistance QTLs selected from thegroup consisting of NLB_2.01, NLB_4.01, NLB_5.01, NLB_6.01, NLB_7.01,and NLB_9.01. In another aspect, a method comprises concurrentlydetecting NLB resistance QTLs NLB_3.01 and NLB_4.02 and at least two ormore NLB resistance QTLs selected from the group consisting of NLB_2.01,NLB_4.01, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect,a method comprises concurrently detecting NLB resistance QTLs NLB_3.01and NLB_4.02 and at least three or more NLB resistance QTLs selectedfrom the group consisting of NLB_2.01, NLB_4.01, NLB_5.01, NLB_6.01,NLB_7.01, and NLB_9.01. In another aspect, a method comprisesconcurrently detecting NLB resistance QTLs NLB_3.01 and NLB_4.02 and atleast four or more NLB resistance QTLs selected from the groupconsisting of NLB_2.01, NLB_4.01, NLB_5.01, NLB_6.01, NLB_7.01, andNLB_9.01. In another aspect, a method comprises concurrently detectingNLB resistance QTLs NLB_3.01 and NLB_4.02 and at least five or more NLBresistance QTLs selected from the group consisting of NLB_2.01,NLB_4.01, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01.

In an aspect, a method comprises concurrently detecting NLB resistanceQTLs NLB_2.01, NLB_4.01, and NLB_4.02. In another aspect, a methodcomprises concurrently detecting NLB resistance QTLs NLB_2.01, NLB_4.01,and NLB_4.02 and at least one or more NLB resistance QTLs selected fromthe group consisting of NLB_3.01, NLB_5.01, NLB_6.01, NLB_7.01, andNLB_9.01. In another aspect, a method comprises concurrently detectingNLB resistance QTLs NLB_2.01, NLB_4.01, and NLB_4.02 and at least two ormore NLB resistance QTLs selected from the group consisting of NLB_3.01,NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a methodcomprises concurrently detecting NLB resistance QTLs NLB_2.01, NLB_4.01,and NLB_4.02 and at least three or more NLB resistance QTLs selectedfrom the group consisting of NLB_3.01, NLB_5.01, NLB_6.01, NLB_7.01, andNLB_9.01. In another aspect, a method comprises concurrently detectingNLB resistance QTLs NLB_2.01, NLB_4.01, and NLB_4.02 and at least fouror more NLB resistance QTLs selected from the group consisting ofNLB_3.01, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01.

In an aspect, a method comprises concurrently detecting NLB resistanceQTLs NLB_2.01 and NLB_4.01. In another aspect, a method comprisesconcurrently detecting NLB resistance QTLs NLB_2.01 and NLB_4.01 and atleast one or more NLB resistance QTLs selected from the group consistingof NLB_3.01, NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. Inanother aspect, a method comprises concurrently detecting NLB resistanceQTLs NLB_2.01 and NLB_4.01 and at least two or more NLB resistance QTLsselected from the group consisting of NLB_3.01, NLB_4.02, NLB_5.01,NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a method comprisesconcurrently detecting NLB resistance QTLs NLB_2.01 and NLB_4.01 and atleast three or more NLB resistance QTLs selected from the groupconsisting of NLB_3.01, NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, andNLB_9.01. In another aspect, a method comprises concurrently detectingNLB resistance QTLs NLB_2.01 and NLB_4.01 and at least four or more NLBresistance QTLs selected from the group consisting of NLB_3.01,NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect,a method comprises concurrently detecting NLB resistance QTLs NLB_2.01and NLB_4.01 and at least five or more NLB resistance QTLs selected fromthe group consisting of NLB_3.01, NLB_4.02, NLB_5.01, NLB_6.01,NLB_7.01, and NLB_9.01.

In an aspect, a method comprises concurrently detecting NLB resistanceQTLs NLB_2.01 and NLB_4.02. In another aspect, a method comprisesconcurrently detecting NLB resistance QTLs NLB_2.01 and NLB_4.02 and atleast one or more NLB resistance QTLs selected from the group consistingof NLB_3.01, NLB_4.01, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. Inanother aspect, a method comprises concurrently detecting NLB resistanceQTLs NLB_2.01 and NLB_4.02 and at least two or more NLB resistance QTLsselected from the group consisting of NLB_3.01, NLB_4.01, NLB_5.01,NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a method comprisesconcurrently detecting NLB resistance QTLs NLB_2.01 and NLB_4.02 and atleast three or more NLB resistance QTLs selected from the groupconsisting of NLB_3.01, NLB_4.01, NLB_5.01, NLB_6.01, NLB_7.01, andNLB_9.01. In another aspect, a method comprises concurrently detectingNLB resistance QTLs NLB_2.01 and NLB_4.02 and at least four or more NLBresistance QTLs selected from the group consisting of NLB_3.01,NLB_4.01, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect,a method comprises concurrently detecting NLB resistance QTLs NLB_2.01and NLB_4.02 and at least five or more NLB resistance QTLs selected fromthe group consisting of NLB_3.01, NLB_4.01, NLB_5.01, NLB_6.01,NLB_7.01, and NLB_9.01.

In another aspect, a method comprises concurrently detecting NLBresistance QTL NLB_4.01 and at least one or more NLB resistance lociselected from the group consisting of Ht1, Ht2, Ht3, and Htn1. Inanother aspect, a method comprises concurrently detecting NLB resistanceQTL NLB_4.01 and at least two or more NLB resistance loci selected fromthe group consisting of Ht1, Ht2, Ht3, and Htn1. In another aspect, amethod comprises concurrently detecting NLB resistance QTL NLB_4.01 andat least three or more NLB resistance loci selected from the groupconsisting of Ht1, Ht2, Ht3, and Htn1. In another aspect, a methodcomprises concurrently detecting NLB resistance QTL NLB_4.02 and atleast one or more NLB resistance loci selected from the group consistingof Ht1, Ht2, Ht3, and Htn1. In another aspect, a method comprisesconcurrently detecting NLB resistance QTL NLB_4.02 and at least two ormore NLB resistance loci selected from the group consisting of Ht1, Ht2,Ht3, and Htn1. In another aspect, a method comprises concurrentlydetecting NLB resistance QTL NLB_4.02 and at least three or more NLBresistance loci selected from the group consisting of Ht1, Ht2, Ht3, andHtn1. In another aspect, a method comprises concurrently detecting NLBresistance QTLs NLB_4.01 and NLB_4.02 and at least one or more NLBresistance loci selected from the group consisting of Ht1, Ht2, Ht3, andHtn1. In another aspect, a method comprises concurrently detecting NLBresistance QTLs NLB_4.01 and NLB_4.02 and at least two or more NLBresistance loci selected from the group consisting of Ht1, Ht2, Ht3, andHtn1. In another aspect, a method comprises concurrently detecting NLBresistance QTLs NLB_4.01 and NLB_4.02 and at least three or more NLBresistance loci selected from the group consisting of Ht1, Ht2, Ht3, andHtn1.

In another aspect, a method comprises concurrently detecting NLBresistance QTL NLB_2.01 and one or more NLB resistance QTLs selectedfrom the group consisting of NLB resistance QTLs NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect,a method comprises concurrently detecting NLB resistance QTL NLB_2.01and two or more NLB resistance QTLs selected from the group consistingof NLB resistance QTLs NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01,NLB_7.01, and NLB_9.01. In another aspect, a method comprisesconcurrently detecting NLB resistance QTL NLB_2.01 and three or more NLBresistance QTLs selected from the group consisting of NLB resistanceQTLs NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, andNLB_9.01. In another aspect, a method comprises concurrently detectingNLB resistance QTL NLB_2.01 and four or more NLB resistance QTLsselected from the group consisting of NLB resistance QTLs NLB_3.01,NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. Inanother aspect, a method comprises concurrently detecting NLB resistanceQTL NLB_2.01 and five or more NLB resistance QTLs selected from thegroup consisting of NLB resistance QTLs NLB_3.01, NLB_4.01, NLB_4.02,NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a methodcomprises concurrently detecting NLB resistance QTL NLB_2.01 and or sixor more NLB resistance QTLs selected from the group consisting of NLBresistance QTLs NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01,NLB_7.01, and NLB_9.01. In another aspect, a method comprisesconcurrently detecting NLB resistance QTL NLB_2.01 and NLB resistanceQTLs NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, andNLB_9.01.

In another aspect, a method comprises concurrently detecting NLBresistance QTL NLB_3.01 and one or more NLB resistance QTLs selectedfrom the group consisting of NLB resistance QTLs NLB_2.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect,a method comprises concurrently detecting NLB resistance QTL NLB_3.01and two or more NLB resistance QTLs selected from the group consistingof NLB resistance QTLs NLB_2.01, NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01,NLB_7.01, and NLB_9.01. In another aspect, a method comprisesconcurrently detecting NLB resistance QTL NLB_3.01 and three or more NLBresistance QTLs selected from the group consisting of NLB resistanceQTLs NLB_2.01, NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, andNLB_9.01. In another aspect, a method comprises concurrently detectingNLB resistance QTL NLB_3.01 and four or more NLB resistance QTLsselected from the group consisting of NLB resistance QTLs NLB_2.01,NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. Inanother aspect, a method comprises concurrently detecting NLB resistanceQTL NLB_3.01 and five or more NLB resistance QTLs selected from thegroup consisting of NLB resistance QTLs NLB_2.01, NLB_4.01, NLB_4.02,NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a methodcomprises concurrently detecting NLB resistance QTL NLB_3.01 and or sixor more NLB resistance QTLs selected from the group consisting of NLBresistance QTLs NLB_2.01, NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01,NLB_7.01, and NLB_9.01. In another aspect, a method comprisesconcurrently detecting NLB resistance QTL NLB_3.01 and NLB resistanceQTLs NLB_2.01, NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, andNLB_9.01.

In another aspect, a method comprises concurrently detecting NLBresistance QTL NLB_4.01 and one or more NLB resistance QTLs selectedfrom the group consisting of NLB resistance QTLs NLB_2.01, NLB_3.01,NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect,a method comprises concurrently detecting NLB resistance QTL NLB_4.01and two or more NLB resistance QTLs selected from the group consistingof NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.02, NLB_5.01, NLB_6.01,NLB_7.01, and NLB_9.01. In another aspect, a method comprisesconcurrently detecting NLB resistance QTL NLB_4.01 and three or more NLBresistance QTLs selected from the group consisting of NLB resistanceQTLs NLB_2.01, NLB_3.01, NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, andNLB_9.01. In another aspect, a method comprises concurrently detectingNLB resistance QTL NLB_4.01 and four or more NLB resistance QTLsselected from the group consisting of NLB resistance QTLs NLB_2.01,NLB_3.01, NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. Inanother aspect, a method comprises concurrently detecting NLB resistanceQTL NLB_4.01 and five or more NLB resistance QTLs selected from thegroup consisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.02,NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a methodcomprises concurrently detecting NLB resistance QTL NLB_4.01 and or sixor more NLB resistance QTLs selected from the group consisting of NLBresistance QTLs NLB_2.01, NLB_3.01, NLB_4.02, NLB_5.01, NLB_6.01,NLB_7.01, and NLB_9.01. In another aspect, a method comprisesconcurrently detecting NLB resistance QTL NLB_4.01 and NLB resistanceQTLs NLB_2.01, NLB_3.01, NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, andNLB_9.01.

In another aspect, a method comprises concurrently detecting NLBresistance QTL NLB_4.02 and one or more NLB resistance QTLs selectedfrom the group consisting of NLB resistance QTLs NLB_2.01, NLB_3.01,NLB_4.01, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect,a method comprises concurrently detecting NLB resistance QTL NLB_4.02and two or more NLB resistance QTLs selected from the group consistingof NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_5.01, NLB_6.01,NLB_7.01, and NLB_9.01. In another aspect, a method comprisesconcurrently detecting NLB resistance QTL NLB_4.02 and three or more NLBresistance QTLs selected from the group consisting of NLB resistanceQTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_5.01, NLB_6.01, NLB_7.01, andNLB_9.01. In another aspect, a method comprises concurrently detectingNLB resistance QTL NLB_4.02 and four or more NLB resistance QTLsselected from the group consisting of NLB resistance QTLs NLB_2.01,NLB_3.01, NLB_4.01, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. Inanother aspect, a method comprises concurrently detecting NLB resistanceQTL NLB_4.02 and five or more NLB resistance QTLs selected from thegroup consisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a methodcomprises concurrently detecting NLB resistance QTL NLB_4.02 and or sixor more NLB resistance QTLs selected from the group consisting of NLBresistance QTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_5.01, NLB_6.01,NLB_7.01, and NLB_9.01. In another aspect, a method comprisesconcurrently detecting NLB resistance QTL NLB_4.02 and NLB resistanceQTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_5.01, NLB_6.01, NLB_7.01, andNLB_9.01.

In another aspect, a method comprises concurrently detecting NLBresistance QTL NLB_5.01 and one or more NLB resistance QTLs selectedfrom the group consisting of NLB resistance QTLs NLB_2.01, NLB_3.01,NLB_4.01, NLB_4.02, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect,a method comprises concurrently detecting NLB resistance QTL NLB_5.01and two or more NLB resistance QTLs selected from the group consistingof NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02, NLB_6.01,NLB_7.01, and NLB_9.01. In another aspect, a method comprisesconcurrently detecting NLB resistance QTL NLB_5.01 and three or more NLBresistance QTLs selected from the group consisting of NLB resistanceQTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02, NLB_6.01, NLB_7.01, andNLB_9.01. In another aspect, a method comprises concurrently detectingNLB resistance QTL NLB_5.01 and four or more NLB resistance QTLsselected from the group consisting of NLB resistance QTLs NLB_2.01,NLB_3.01, NLB_4.01, NLB_4.02, NLB_6.01, NLB_7.01, and NLB_9.01. Inanother aspect, a method comprises concurrently detecting NLB resistanceQTL NLB_5.01 and five or more NLB resistance QTLs selected from thegroup consisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a methodcomprises concurrently detecting NLB resistance QTL NLB_5.01 and or sixor more NLB resistance QTLs selected from the group consisting of NLBresistance QTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02, NLB_6.01,NLB_7.01, and NLB_9.01. In another aspect, a method comprisesconcurrently detecting NLB resistance QTL NLB_5.01 and NLB resistanceQTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02, NLB_6.01, NLB_7.01, andNLB_9.01.

In another aspect, a method comprises concurrently detecting NLBresistance QTL NLB_6.01 and one or more NLB resistance QTLs selectedfrom the group consisting of NLB resistance QTLs NLB_2.01, NLB_3.01,NLB_4.01, NLB_4.02, NLB_5.01, NLB_7.01, and NLB_9.01. In another aspect,a method comprises concurrently detecting NLB resistance QTL NLB_6.01and two or more NLB resistance QTLs selected from the group consistingof NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01,NLB_7.01, and NLB_9.01. In another aspect, a method comprisesconcurrently detecting NLB resistance QTL NLB_6.01 and three or more NLBresistance QTLs selected from the group consisting of NLB resistanceQTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01, NLB_7.01, andNLB_9.01. In another aspect, a method comprises concurrently detectingNLB resistance QTL NLB_6.01 and four or more NLB resistance QTLsselected from the group consisting of NLB resistance QTLs NLB_2.01,NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01, NLB_7.01, and NLB_9.01. Inanother aspect, a method comprises concurrently detecting NLB resistanceQTL NLB_6.01 and five or more NLB resistance QTLs selected from thegroup consisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_7.01, and NLB_9.01. In another aspect, a methodcomprises concurrently detecting NLB resistance QTL NLB_6.01 and or sixor more NLB resistance QTLs selected from the group consisting of NLBresistance QTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01,NLB_7.01, and NLB_9.01. In another aspect, a method comprisesconcurrently detecting NLB resistance QTL NLB_6.01 and NLB resistanceQTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01, NLB_7.01, andNLB_9.01.

In another aspect, a method comprises concurrently detecting NLBresistance QTL NLB_7.01 and one or more NLB resistance QTLs selectedfrom the group consisting of NLB resistance QTLs NLB_2.01, NLB_3.01,NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01, and NLB_9.01. In another aspect,a method comprises concurrently detecting NLB resistance QTL NLB_7.01and two or more NLB resistance QTLs selected from the group consistingof NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01,NLB_6.01, and NLB_9.01. In another aspect, a method comprisesconcurrently detecting NLB resistance QTL NLB_7.01 and three or more NLBresistance QTLs selected from the group consisting of NLB resistanceQTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01, andNLB_9.01. In another aspect, a method comprises concurrently detectingNLB resistance QTL NLB_7.01 and four or more NLB resistance QTLsselected from the group consisting of NLB resistance QTLs NLB_2.01,NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01, and NLB_9.01. Inanother aspect, a method comprises concurrently detecting NLB resistanceQTL NLB_7.01 and five or more NLB resistance QTLs selected from thegroup consisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_6.01, and NLB_9.01. In another aspect, a methodcomprises concurrently detecting NLB resistance QTL NLB_7.01 and or sixor more NLB resistance QTLs selected from the group consisting of NLBresistance QTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01,NLB_6.01, and NLB_9.01. In another aspect, a method comprisesconcurrently detecting NLB resistance QTL NLB_7.01 and NLB resistanceQTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01, andNLB_9.01.

In another aspect, a method comprises concurrently detecting NLBresistance QTL NLB_9.01 and one or more NLB resistance QTLs selectedfrom the group consisting of NLB resistance QTLs NLB_2.01, NLB_3.01,NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01, and NLB_7.01. In another aspect,a method comprises concurrently detecting NLB resistance QTL NLB_9.01and two or more NLB resistance QTLs selected from the group consistingof NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01,NLB_6.01, and NLB_7.01. In another aspect, a method comprisesconcurrently detecting NLB resistance QTL NLB_9.01 and three or more NLBresistance QTLs selected from the group consisting of NLB resistanceQTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01, andNLB_7.01. In another aspect, a method comprises concurrently detectingNLB resistance QTL NLB_9.01 and four or more NLB resistance QTLsselected from the group consisting of NLB resistance QTLs NLB_2.01,NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01, and NLB_7.01. Inanother aspect, a method comprises concurrently detecting NLB resistanceQTL NLB_9.01 and five or more NLB resistance QTLs selected from thegroup consisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_6.01, and NLB_7.01. In another aspect, a methodcomprises concurrently detecting NLB resistance QTL NLB_9.01 and or sixor more NLB resistance QTLs selected from the group consisting of NLBresistance QTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01,NLB_6.01, and NLB_7.01. In another aspect, a method comprisesconcurrently detecting NLB resistance QTL NLB_9.01 and NLB resistanceQTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01, andNLB_7.01.

In an aspect, this disclosure provides a method of producing a cornplant with enhanced NLB resistance, which method comprising the stepsof: (a) crossing a first corn plant comprising an NLB resistance QTLwith a second corn plant of a different genotype to produce one or moreprogeny plants or seeds; (b) selecting a progeny plant or seedcomprising an NLB resistance allele of a polymorphic locus linked to anNLB resistance QTL, wherein a polymorphic locus is in a chromosomalsegment flanked by any two of marker loci SEQ ID NOs: 1 to 18, any twoof marker loci SEQ ID NOs: 19 to 31, any two of marker loci SEQ ID NOs:32 to 52 and 471 to 475, any two of marker loci SEQ ID NOs: 53 to 65 and446 to 468, any two of marker loci SEQ ID NOs: 66 to 84, any two ofmarker loci SEQ ID NOs: 85 to 89 and 476 to 482, or marker loci SEQ IDNOs: 469 and 470; (c) crossing the selected progeny plant with itself orthe second corn plant to produce one or more further progeny plants orseeds; and (d) selecting a further progeny plant or seed comprising theNLB resistance allele. In an aspect, the further progeny plant in step(d) is an F₂ to F₇ progeny plant. In another aspect, the further progenyplant in step (d) comprises 2 to 7 generations of backcrossing. In yetanother aspect, a method comprises using marker-assisted selection toselect an NLB resistance allele in at least one polymorphic locusselected from the group consisting of SEQ ID NOs: 1-89 and 446-482.

In an aspect, this disclosure provides a method of obtaining a cornplant, seed, or cell with enhanced NLB resistance, which methodcomprises the steps of: (a) detecting in a population of corn plants,seeds, or cells a plant or seed comprising an NLB resistance allele at apolymorphic locus in a chromosomal segment flanked by SEQ ID NOs: 1 to18, any two of marker loci SEQ ID NOs: 19 to 31, any two of marker lociSEQ ID NOs: 32 to 52 and 471 to 475, any two of marker loci SEQ ID NOs:53 to 65 and 446 to 468, any two of marker loci SEQ ID NOs: 66 to 84,any two of marker loci SEQ ID NOs: 85 to 89 and 476 to 482, or markerloci SEQ ID NOs: 469 and 470; and (b) selecting the corn plant, seed, orcell from the population based on the presence of the NLB resistanceallele.

In an aspect, this disclosure provides a method of producing a cornplant with enhanced NLB resistance, which method comprising the stepsof: (a) crossing a first corn plant comprising an NLB resistancehaplotype with a second corn plant of a different genotype to produceone or more progeny plants or seeds; (b) selecting a progeny plant orseed based on the presence of the NLB resistance haplotype, wherein thehaplotype comprises resistance alleles of two or more polymorphic lociin a chromosomal interval flanked by: any two marker loci selected fromthe group consisting of SEQ ID NOs: 1 to 18, any two of marker loci SEQID NOs: 19 to 31, any two of marker loci SEQ ID NOs: 32 to 52 and 471 to475, any two of marker loci SEQ ID NOs: 53 to 65 and 446 to 468, any twoof marker loci SEQ ID NOs: 66 to 84, any two of marker loci SEQ ID NOs:85 to 89 and 476 to 482, or marker loci SEQ ID NOs: 469 and 470.

In an aspect, this disclosure provides a method of obtaining a cornplant, seed, or cell with enhanced NLB resistance, which methodcomprising the steps of: (a) detecting in a population of corn plants,seeds, or cells a plant or seed comprising an NLB resistance haplotype,wherein the haplotype comprises resistance alleles of two or morepolymorphic loci in a chromosomal interval flanked by: any two markerloci selected from the group consisting of SEQ ID NOs: 12 to 15; any twomarker loci selected from the group consisting of SEQ ID NOs: 22 to 25;any two marker loci selected from the group consisting of SEQ ID NOs: 37to 42 and 474; any two marker loci selected from the group consisting ofSEQ ID NOs: 44 to 49; any two marker loci selected from the groupconsisting of SEQ ID NOs: 57 to 62 and 458 to 466; any two marker lociselected from the group consisting of SEQ ID NOs: 79 to 81; any twomarker loci selected from the group consisting of SEQ ID NOs: 87 to 89and 477 to 480; and marker loci SEQ ID NOs: 469 and 470; and (b)selecting a corn plant, seed, or cell from the population based on thepresence of the NLB resistance haplotype. In another aspect, an NLBresistance haplotype comprises resistance alleles of two or morepolymorphic loci selected from the group consisting of SEQ ID NOs:12-15; 22-24; 37-41 and 474; 44-46; 60-62 and 464-466; 79-81; 87-89,477, and 480; and 469-470.

In an aspect, this disclosure provides a method of obtaining a cornplant, seed, or cell with enhanced NLB resistance, which methodcomprising the steps of: (a) detecting in a population of corn plants,seeds, or cells a corn plant, seed, or cell comprising an NLB resistancehaplotype, wherein the haplotype comprises resistance alleles of two ormore polymorphic loci in a chromosomal interval flanked by: any twomarker loci selected from the group consisting of SEQ ID NOs: 8 to 18;any two marker loci selected from the group consisting of SEQ ID NOs: 21to 29; any two marker loci selected from the group consisting of SEQ IDNOs: 33 to 42, 473, and 474; any two marker loci selected from the groupconsisting of SEQ ID NOs: 43 to 49 and 475; any two marker loci selectedfrom the group consisting of SEQ ID NOs: 57 to 64 and 458 to 468; anytwo marker loci selected from the group consisting of SEQ ID NOs: 74 to82; any two marker loci selected from the group consisting of SEQ IDNOs: 86 to 89, 476, 477, 479, and 480; and marker loci SEQ ID NOs: 469and 470; and (b) selecting a corn plant, seed, or cell from thepopulation based on the presence of the NLB resistance haplotype. In yetanother aspect, an NLB resistance haplotype comprises resistance allelesof two or more polymorphic loci selected from the group consisting ofSEQ ID NOs: 8-18; 21-29; 33-42, 473, and 474; 43-49 and 475; 57-64 and458-468; 74-82; 86-89, 476, 477, 479, and 480; and 469-470.

In an aspect, this disclosure provides a method for selecting a cornplant, seed, or cell, which method comprising the steps of: (a)isolating nucleic acids from a corn plant, seed, or cell; (b) analyzingthe nucleic acids to detect a polymorphic marker associated with an NLBresistance QTL selected from the group consisting of NLB resistance QTLsNLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01,and NLB_9.01; and (c) selecting a corn plant, seed, or cell comprisingthe NLB resistance QTL.

In an aspect, this disclosure provides a method for selecting a cornplant, seed, or cell, which method comprising the steps of: (a)detecting in a population of corn plants, seeds, or cells a corn plant,seed, or cell comprising an NLB resistance allele of a marker locusassociated with an NLB resistance QTL selected from the group consistingof NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01,NLB_6.01, NLB_7.01, and NLB_9.01; and (b) selecting a corn plant, seed,or cell comprising the NLB resistance allele.

In an aspect, this disclosure provides a method for evaluating acollection of corn germplasm, which method comprising the steps of: (a)obtaining a collection of corn germplasm; (b) isolating nucleic acidsfrom each germplasm; (c) assaying the nucleic acids for one or moremarkers linked to an NLB resistance QTL selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01; and (d) selectinggermplasm comprising an NLB resistance QTL based on the marker assay.

In an aspect, a method provided herein comprises genotyping by a markerassay. As an example, a method provided herein comprises marker-assistedselection. As another example, a method provided herein comprisesassaying a SNP marker. In yet another example, a method provided hereincomprises the use of an oligonucleotide probe. In a further example, amethod provided herein comprises using an oligonucleotide probe adjacentto a polymorphic nucleotide position in a marker locus being genotyped.

As an example, a corn plant or seed provided herein can be an inbred, ahybrid, a transgenic, a haploid, a doubled haploid, or in anagronomically elite background. These groups are not mutually exclusive,and a corn plant or seed could be in two or more groups (e.g., a plantcould be a transgenic hybrid, another plant could be an inbred doubledhaploid, etc.).

In an aspect, a method provided herein comprises genotyping a cornplant, seed, or cell at a polymorphic marker locus within about 20 cM ofany one of marker loci SEQ ID NOs: 1-89 and 446-482. In an aspect, amethod provided herein comprises genotyping a corn plant, seed, or cellat a polymorphic marker locus within about 15 cM of any one of markerloci SEQ ID NOs: 1-89 and 446-482. In an aspect, a method providedherein comprises genotyping a corn plant, seed, or cell at a polymorphicmarker locus within about 10 cM of any one of marker loci SEQ ID NOs:1-89 and 446-482. In an aspect, a method provided herein comprisesgenotyping a corn plant, seed, or cell at a polymorphic marker locuswithin about 5 cM of any one of marker loci SEQ ID NOs: 1-89 and446-482. In an aspect, a method provided herein comprises genotyping acorn plant, seed, or cell at a polymorphic marker locus within about 4cM of any one of marker loci SEQ ID NOs: 1-89 and 446-482. In an aspect,a method provided herein comprises genotyping a corn plant, seed, orcell at a polymorphic marker locus within about 3 cM of any one ofmarker loci SEQ ID NOs: 1-89 and 446-482. In an aspect, a methodprovided herein comprises genotyping a corn plant, seed, or cell at apolymorphic marker locus within about 2 cM of any one of marker loci SEQID NOs: 1-89 and 446-482. In an aspect, a method provided hereincomprises genotyping a corn plant, seed, or cell at a polymorphic markerlocus within about 1 cM of any one of marker loci SEQ ID NOs: 1-89 and446-482. In an aspect, a method provided herein comprises genotyping acorn plant, seed, or cell at a polymorphic marker locus within about 0.5cM of any one of marker loci SEQ ID NOs: 1-89 and 446-482. In an aspect,a method provided herein comprises genotyping a corn plant, seed, orcell at a polymorphic marker locus within less than about 0.5 cM of anyone of marker loci SEQ ID NOs: 1-89 and 446-482. In an aspect, thisdisclosure provides a method comprising genotyping a polymorphic locusselected from the group consisting of SEQ ID NOs: 1-89 and 446-482.

In an aspect, a method provided herein comprises genotyping a cornplant, seed, or cell at a marker locus associated with NLB resistanceQTL NLB_2.01, which NLB resistance QTL NLB_2.01 is located in achromosomal interval flanked by any two of the marker loci selected fromthe group consisting of SEQ ID NOs: 1 to 18. In another aspect, a methodprovided herein comprises genotyping a corn plant, seed, or cell at amarker locus associated with NLB resistance QTL NLB_2.01, which NLBresistance QTL NLB_2.01 is located in a chromosomal interval flanked byany two of the marker loci selected from the group consisting of SEQ IDNOs: 12 to 15. In another aspect, a method provided herein comprisesgenotyping a corn plant, seed, or cell at a marker locus associated withNLB resistance QTL NLB_2.01, which NLB resistance QTL NLB_2.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 8 to 18.

In an aspect, a method provided herein comprises genotyping a cornplant, seed, or cell at a marker locus within about 20 cM of NLBresistance QTL NLB_2.01, which NLB resistance QTL NLB_2.01 is located ina chromosomal interval flanked by any two of the marker loci selectedfrom the group consisting of SEQ ID NOs: 1 to 18. In an aspect, a methodprovided herein comprises genotyping a corn plant, seed, or cell at amarker locus within about 15 cM of NLB resistance QTL NLB_2.01, whichNLB resistance QTL NLB_2.01 is located in a chromosomal interval flankedby any two of the marker loci selected from the group consisting of SEQID NOs: 1 to 18. In an aspect, a method provided herein comprisesgenotyping a corn plant, seed, or cell at a marker locus within about 10cM of NLB resistance QTL NLB_2.01, which NLB resistance QTL NLB_2.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 1 to 18. In an aspect,a method provided herein comprises genotyping a corn plant, seed, orcell at a marker locus within about 5 cM of NLB resistance QTL NLB_2.01,which NLB resistance QTL NLB_2.01 is located in a chromosomal intervalflanked by any two of the marker loci selected from the group consistingof SEQ ID NOs: 1 to 18. In an aspect, a method provided herein comprisesgenotyping a corn plant, seed, or cell at a marker locus within about 4cM of NLB resistance QTL NLB_2.01, which NLB resistance QTL NLB_2.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 1 to 18. In an aspect,a method provided herein comprises genotyping a corn plant, seed, orcell at a marker locus within about 3 cM of NLB resistance QTL NLB_2.01,which NLB resistance QTL NLB_2.01 is located in a chromosomal intervalflanked by any two of the marker loci selected from the group consistingof SEQ ID NOs: 1 to 18. In an aspect, a method provided herein comprisesgenotyping a corn plant, seed, or cell at a marker locus within about 2cM of NLB resistance QTL NLB_2.01, which NLB resistance QTL NLB_2.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 1 to 18. In an aspect,a method provided herein comprises genotyping a corn plant, seed, orcell at a marker locus within about 1 cM of NLB resistance QTL NLB_2.01,which NLB resistance QTL NLB_2.01 is located in a chromosomal intervalflanked by any two of the marker loci selected from the group consistingof SEQ ID NOs: 1 to 18. In an aspect, a method provided herein comprisesgenotyping a corn plant, seed, or cell at a marker locus within about0.5 cM of NLB resistance QTL NLB_2.01, which NLB resistance QTL NLB_2.01is located in a chromosomal interval flanked by any two of the markerloci selected from the group consisting of SEQ ID NOs: 1 to 18. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus within less than about 0.5 cM of NLBresistance QTL NLB_2.01, which NLB resistance QTL NLB_2.01 is located ina chromosomal interval flanked by any two of the marker loci selectedfrom the group consisting of SEQ ID NOs: 1 to 18. In an aspect, a methodprovided herein comprises genotyping a corn plant, seed, or cell at amarker locus associated with NLB resistance QTL NLB_3.01, which NLBresistance QTL NLB_3.01 is located in a chromosomal interval flanked byany two of the marker loci selected from the group consisting of SEQ IDNOs: 19 to 31. In another aspect, a method provided herein comprisesgenotyping a corn plant, seed, or cell at a marker locus associated withNLB resistance QTL NLB_3.01, which NLB resistance QTL NLB_3.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 22 to 25. In anotheraspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with NLB resistance QTLNLB_3.01, which NLB resistance QTL NLB_3.01 is located in a chromosomalinterval flanked by any two of the marker loci selected from the groupconsisting of SEQ ID NOs: 21 to 29.

In an aspect, a method provided herein comprises genotyping a cornplant, seed, or cell at a marker locus associated with and within about20 cM of NLB resistance QTL NLB_3.01, which NLB resistance QTL NLB_3.01is located in a chromosomal interval flanked by any two of the markerloci selected from the group consisting of SEQ ID NOs: 19 to 31. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with and within about 15 cMof NLB resistance QTL NLB_3.01, which NLB resistance QTL NLB_3.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 19 to 31. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with and within about 10 cMof NLB resistance QTL NLB_3.01, which NLB resistance QTL NLB_3.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 19 to 31. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with and within about 5 cM ofNLB resistance QTL NLB_3.01, which NLB resistance QTL NLB_3.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 19 to 31. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with and within about 4 cM ofNLB resistance QTL NLB_3.01, which NLB resistance QTL NLB_3.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 19 to 31. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with and within about 3 cM ofNLB resistance QTL NLB_3.01, which NLB resistance QTL NLB_3.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 19 to 31. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with and within about 2 cM ofNLB resistance QTL NLB_3.01, which NLB resistance QTL NLB_3.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 19 to 31. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with and within about 1 cM ofNLB resistance QTL NLB_3.01, which NLB resistance QTL NLB_3.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 19 to 31. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with and within about 0.5 cMof NLB resistance QTL NLB_3.01, which NLB resistance QTL NLB_3.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 19 to 31. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus within less than about 0.5 cM of NLBresistance QTL NLB_3.01, which NLB resistance QTL NLB_3.01 is located ina chromosomal interval flanked by any two of the marker loci selectedfrom the group consisting of SEQ ID NOs: 19 to 31.

In an aspect, a method provided herein comprises genotyping a cornplant, seed, or cell at a marker locus associated with NLB resistanceQTL NLB_4.01, which NLB resistance QTL NLB_4.01 is located in achromosomal interval flanked by any two of the marker loci selected fromthe group consisting of SEQ ID NOs: 32 to 52 and 471 to 475. In anotheraspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with NLB resistance QTLNLB_4.01, which NLB resistance QTL NLB_4.01 is located in a chromosomalinterval flanked by any two of the marker loci selected from the groupconsisting of SEQ ID NOs: 37 to 42 and 474. In another aspect, a methodprovided herein comprises genotyping a corn plant, seed, or cell at amarker locus associated with NLB resistance QTL NLB_4.01, which NLBresistance QTL NLB_4.01 is located in a chromosomal interval flanked byany two of the marker loci selected from the group consisting of SEQ IDNOs: 33 to 42, 473, and 474.

In an aspect, a method provided herein comprises genotyping a cornplant, seed, or cell at a marker locus associated with and within about20 cM of NLB resistance QTL NLB_4.01, which NLB resistance QTL NLB_4.01is located in a chromosomal interval flanked by any two of the markerloci selected from the group consisting of SEQ ID NOs: 32 to 52 and 471to 475. In an aspect, a method provided herein comprises genotyping acorn plant, seed, or cell at a marker locus associated with and withinabout 15 cM of NLB resistance QTL NLB_4.01, which NLB resistance QTLNLB_4.01 is located in a chromosomal interval flanked by any two of themarker loci selected from the group consisting of SEQ ID NOs: 32 to 52and 471 to 475. In an aspect, a method provided herein comprisesgenotyping a corn plant, seed, or cell at a marker locus associated withand within about 10 cM of NLB resistance QTL NLB_4.01, which NLBresistance QTL NLB_4.01 is located in a chromosomal interval flanked byany two of the marker loci selected from the group consisting of SEQ IDNOs: 32 to 52 and 471 to 475. In an aspect, a method provided hereincomprises genotyping a corn plant, seed, or cell at a marker locusassociated with and within about 5 cM of NLB resistance QTL NLB_4.01,which NLB resistance QTL NLB_4.01 is located in a chromosomal intervalflanked by any two of the marker loci selected from the group consistingof SEQ ID NOs: 32 to 52 and 471 to 475. In an aspect, a method providedherein comprises genotyping a corn plant, seed, or cell at a markerlocus associated with and within about 4 cM of NLB resistance QTLNLB_4.01, which NLB resistance QTL NLB_4.01 is located in a chromosomalinterval flanked by any two of the marker loci selected from the groupconsisting of SEQ ID NOs: 32 to 52 and 471 to 475. In an aspect, amethod provided herein comprises genotyping a corn plant, seed, or cellat a marker locus associated with and within about 3 cM of NLBresistance QTL NLB_4.01, which NLB resistance QTL NLB_4.01 is located ina chromosomal interval flanked by any two of the marker loci selectedfrom the group consisting of SEQ ID NOs: 32 to 52 and 471 to 475. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with and within about 2 cM ofNLB resistance QTL NLB_4.01, which NLB resistance QTL NLB_4.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 32 to 52 and 471 to475. In an aspect, a method provided herein comprises genotyping a cornplant, seed, or cell at a marker locus associated with and within about1 cM of NLB resistance QTL NLB_4.01, which NLB resistance QTL NLB_4.01is located in a chromosomal interval flanked by any two of the markerloci selected from the group consisting of SEQ ID NOs: 32 to 52 and 471to 475. In an aspect, a method provided herein comprises genotyping acorn plant, seed, or cell at a marker locus associated with and withinabout 0.5 cM of NLB resistance QTL NLB_4.01, which NLB resistance QTLNLB_4.01 is located in a chromosomal interval flanked by any two of themarker loci selected from the group consisting of SEQ ID NOs: 32 to 52and 471 to 475. In an aspect, a method provided herein comprisesgenotyping a corn plant, seed, or cell at a marker locus within lessthan about 0.5 cM of NLB resistance QTL NLB_4.01, which NLB resistanceQTL NLB_4.01 is located in a chromosomal interval flanked by any two ofthe marker loci selected from the group consisting of SEQ ID NOs: 32 to52 and 471 to 475.

In an aspect, a method provided herein comprises genotyping a cornplant, seed, or cell at a marker locus associated with NLB resistanceQTL NLB_4.02, which NLB resistance QTL NLB_4.02 is located in achromosomal interval flanked by any two of the marker loci selected fromthe group consisting of SEQ ID NOs: 32 to 52 and 471 to 475. In anotheraspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with NLB resistance QTLNLB_4.02, which NLB resistance QTL NLB_4.02 is located in a chromosomalinterval flanked by any two of the marker loci selected from the groupconsisting of SEQ ID NOs: 44 to 49. In another aspect, a method providedherein comprises genotyping a corn plant, seed, or cell at a markerlocus associated with NLB resistance QTL NLB_4.02, which NLB resistanceQTL NLB_4.02 is located in a chromosomal interval flanked by any two ofthe marker loci selected from the group consisting of SEQ ID NOs: 43 to49 and 475.

In an aspect, a method provided herein comprises genotyping a cornplant, seed, or cell at a marker locus associated with and within about20 cM of NLB resistance QTL NLB_4.02, which NLB resistance QTL NLB_4.02is located in a chromosomal interval flanked by any two of the markerloci selected from the group consisting of SEQ ID NOs: 32 to 52 and 471to 475. In an aspect, a method provided herein comprises genotyping acorn plant, seed, or cell at a marker locus associated with and withinabout 15 cM of NLB resistance QTL NLB_4.02, which NLB resistance QTLNLB_4.02 is located in a chromosomal interval flanked by any two of themarker loci selected from the group consisting of SEQ ID NOs: 32 to 52and 471 to 475. In an aspect, a method provided herein comprisesgenotyping a corn plant, seed, or cell at a marker locus associated withand within about 10 cM of NLB resistance QTL NLB_4.02, which NLBresistance QTL NLB_4.02 is located in a chromosomal interval flanked byany two of the marker loci selected from the group consisting of SEQ IDNOs: 32 to 52 and 471 to 475. In an aspect, a method provided hereincomprises genotyping a corn plant, seed, or cell at a marker locusassociated with and within about 5 cM of NLB resistance QTL NLB_4.02,which NLB resistance QTL NLB_4.02 is located in a chromosomal intervalflanked by any two of the marker loci selected from the group consistingof SEQ ID NOs: 32 to 52 and 471 to 475. In an aspect, a method providedherein comprises genotyping a corn plant, seed, or cell at a markerlocus associated with and within about 4 cM of NLB resistance QTLNLB_4.02, which NLB resistance QTL NLB_4.02 is located in a chromosomalinterval flanked by any two of the marker loci selected from the groupconsisting of SEQ ID NOs: 32 to 52 and 471 to 475. In an aspect, amethod provided herein comprises genotyping a corn plant, seed, or cellat a marker locus associated with and within about 3 cM of NLBresistance QTL NLB_4.02, which NLB resistance QTL NLB_4.02 is located ina chromosomal interval flanked by any two of the marker loci selectedfrom the group consisting of SEQ ID NOs: 32 to 52 and 471 to 475. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with and within about 2 cM ofNLB resistance QTL NLB_4.02, which NLB resistance QTL NLB_4.02 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 32 to 52 and 471 to475. In an aspect, a method provided herein comprises genotyping a cornplant, seed, or cell at a marker locus associated with and within about1 cM of NLB resistance QTL NLB_4.02, which NLB resistance QTL NLB_4.02is located in a chromosomal interval flanked by any two of the markerloci selected from the group consisting of SEQ ID NOs: 32 to 52 and 471to 475. In an aspect, a method provided herein comprises genotyping acorn plant, seed, or cell at a marker locus associated with and withinabout 0.5 cM of NLB resistance QTL NLB_4.02, which NLB resistance QTLNLB_4.02 is located in a chromosomal interval flanked by any two of themarker loci selected from the group consisting of SEQ ID NOs: 32 to 52and 471 to 475. In an aspect, a method provided herein comprisesgenotyping a corn plant, seed, or cell at a marker locus within lessthan about 0.5 cM of NLB resistance QTL NLB_4.02, which NLB resistanceQTL NLB_4.02 is located in a chromosomal interval flanked by any two ofthe marker loci selected from the group consisting of SEQ ID NOs: 32 to52 and 471 to 475.

In an aspect, a method provided herein comprises genotyping a cornplant, seed, or cell at a marker locus associated with NLB resistanceQTL NLB_5.01, which NLB resistance QTL NLB_5.01 is located in achromosomal interval flanked by any two of the marker loci selected fromthe group consisting of SEQ ID NOs: 53 to 65 and 446 to 468. In anotheraspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with NLB resistance QTLNLB_5.01, which NLB resistance QTL NLB_5.01 is located in a chromosomalinterval flanked by any two of the marker loci selected from the groupconsisting of SEQ ID NOs: 57 to 62 and 458 to 466. In another aspect, amethod provided herein comprises genotyping a corn plant, seed, or cellat a marker locus associated with NLB resistance QTL NLB_5.01, which NLBresistance QTL NLB_5.01 is located in a chromosomal interval flanked byany two of the marker loci selected from the group consisting of SEQ IDNOs: 57 to 64 and 458 to 468.

In an aspect, a method provided herein comprises genotyping a cornplant, seed, or cell at a marker locus associated with and within about20 cM of NLB resistance QTL NLB_5.01, which NLB resistance QTL NLB_5.01is located in a chromosomal interval flanked by any two of the markerloci selected from the group consisting of SEQ ID NOs: 53 to 65 and 446to 468. In an aspect, a method provided herein comprises genotyping acorn plant, seed, or cell at a marker locus associated with and withinabout 15 cM of NLB resistance QTL NLB_5.01, which NLB resistance QTLNLB_5.01 is located in a chromosomal interval flanked by any two of themarker loci selected from the group consisting of SEQ ID NOs: 53 to 65and 446 to 468. In an aspect, a method provided herein comprisesgenotyping a corn plant, seed, or cell at a marker locus associated withand within about 10 cM of NLB resistance QTL NLB_5.01, which NLBresistance QTL NLB_5.01 is located in a chromosomal interval flanked byany two of the marker loci selected from the group consisting of SEQ IDNOs: 53 to 65 and 446 to 468. In an aspect, a method provided hereincomprises genotyping a corn plant, seed, or cell at a marker locusassociated with and within about 5 cM of NLB resistance QTL NLB_5.01,which NLB resistance QTL NLB_5.01 is located in a chromosomal intervalflanked by any two of the marker loci selected from the group consistingof SEQ ID NOs: 53 to 65 and 446 to 468. In an aspect, a method providedherein comprises genotyping a corn plant, seed, or cell at a markerlocus associated with and within about 4 cM of NLB resistance QTLNLB_5.01, which NLB resistance QTL NLB_5.01 is located in a chromosomalinterval flanked by any two of the marker loci selected from the groupconsisting of SEQ ID NOs: 53 to 65 and 446 to 468. In an aspect, amethod provided herein comprises genotyping a corn plant, seed, or cellat a marker locus associated with and within about 3 cM of NLBresistance QTL NLB_5.01, which NLB resistance QTL NLB_5.01 is located ina chromosomal interval flanked by any two of the marker loci selectedfrom the group consisting of SEQ ID NOs: 53 to 65 and 446 to 468. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with and within about 2 cM ofNLB resistance QTL NLB_5.01, which NLB resistance QTL NLB_5.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 53 to 65 and 446 to468. In an aspect, a method provided herein comprises genotyping a cornplant, seed, or cell at a marker locus associated with and within about1 cM of NLB resistance QTL NLB_5.01, which NLB resistance QTL NLB_5.01is located in a chromosomal interval flanked by any two of the markerloci selected from the group consisting of SEQ ID NOs: 53 to 65 and 446to 468. In an aspect, a method provided herein comprises genotyping acorn plant, seed, or cell at a marker locus associated with and withinabout 0.5 cM of NLB resistance QTL NLB_5.01, which NLB resistance QTLNLB_5.01 is located in a chromosomal interval flanked by any two of themarker loci selected from the group consisting of SEQ ID NOs: 53 to 65and 446 to 468. In an aspect, a method provided herein comprisesgenotyping a corn plant, seed, or cell at a marker locus within lessthan about 0.5 cM of NLB resistance QTL NLB_5.01, which NLB resistanceQTL NLB_3.01 is located in a chromosomal interval flanked by any two ofthe marker loci selected from the group consisting of SEQ ID NOs: 53 to65 and 446 to 468.

In an aspect, a method provided herein comprises genotyping a cornplant, seed, or cell at a marker locus associated with NLB resistanceQTL NLB_6.01, which NLB resistance QTL NLB_6.01 is located in achromosomal interval flanked by any two of the marker loci selected fromthe group consisting of SEQ ID NOs: 66 to 84. In another aspect, amethod provided herein comprises genotyping a corn plant, seed, or cellat a marker locus associated with NLB resistance QTL NLB_6.01, which NLBresistance QTL NLB_6.01 is located in a chromosomal interval flanked byany two of the marker loci selected from the group consisting of SEQ IDNOs: 79 to 81. In another aspect, a method provided herein comprisesgenotyping a corn plant, seed, or cell at a marker locus associated withNLB resistance QTL NLB_6.01, which NLB resistance QTL NLB_6.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 74 to 82.

In an aspect, a method provided herein comprises genotyping a cornplant, seed, or cell at a marker locus associated with and within about20 cM of NLB resistance QTL NLB_6.01, which NLB resistance QTL NLB_6.01is located in a chromosomal interval flanked by any two of the markerloci selected from the group consisting of SEQ ID NOs: 74 to 82. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with and within about 15 cMof NLB resistance QTL NLB_6.01, which NLB resistance QTL NLB_6.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 74 to 82. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with and within about 10 cMof NLB resistance QTL NLB_6.01, which NLB resistance QTL NLB_6.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 74 to 82. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with and within about 5 cM ofNLB resistance QTL NLB_6.01, which NLB resistance QTL NLB_6.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 74 to 82. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with and within about 4 cM ofNLB resistance QTL NLB_6.01, which NLB resistance QTL NLB_6.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 74 to 82. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with and within about 3 cM ofNLB resistance QTL NLB_6.01, which NLB resistance QTL NLB_6.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 74 to 82. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with and within about 2 cM ofNLB resistance QTL NLB_6.01, which NLB resistance QTL NLB_6.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 74 to 82. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with and within about 1 cM ofNLB resistance QTL NLB_6.01, which NLB resistance QTL NLB_6.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 74 to 82. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with and within about 0.5 cMof NLB resistance QTL NLB_6.01, which NLB resistance QTL NLB_6.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 74 to 82. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus within less than about 0.5 cM of NLBresistance QTL NLB_6.01, which NLB resistance QTL NLB_3.01 is located ina chromosomal interval flanked by any two of the marker loci selectedfrom the group consisting of SEQ ID NOs: 74 to 82.

In an aspect, a method provided herein comprises genotyping a cornplant, seed, or cell at a marker locus associated with NLB resistanceQTL NLB_7.01, which NLB resistance QTL NLB_7.01 is located in achromosomal interval flanked by the marker loci SEQ ID NOs: 469 and 470.

In an aspect, a method provided herein comprises genotyping a cornplant, seed, or cell at a marker locus associated with and within about20 cM of NLB resistance QTL NLB_7.01, which NLB resistance QTL NLB_7.01is located in a chromosomal interval flanked by any two of the markerloci selected from the group consisting of SEQ ID NOs: 469 and 470. Inan aspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with and within about 15 cMof NLB resistance QTL NLB_7.01, which NLB resistance QTL NLB_7.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 469 and 470. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with and within about 10 cMof NLB resistance QTL NLB_7.01, which NLB resistance QTL NLB_7.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 469 and 470. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with and within about 5 cM ofNLB resistance QTL NLB_7.01, which NLB resistance QTL NLB_7.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 469 and 470. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with and within about 4 cM ofNLB resistance QTL NLB_7.01, which NLB resistance QTL NLB_7.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 469 and 470. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with and within about 3 cM ofNLB resistance QTL NLB_7.01, which NLB resistance QTL NLB_7.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 469 and 470. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with and within about 2 cM ofNLB resistance QTL NLB_7.01, which NLB resistance QTL NLB_7.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 469 and 470. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with and within about 1 cM ofNLB resistance QTL NLB_7.01, which NLB resistance QTL NLB_7.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 469 and 470. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with and within about 0.5 cMof NLB resistance QTL NLB_7.01, which NLB resistance QTL NLB_7.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 469 and 470. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus within less than about 0.5 cM of NLBresistance QTL NLB_7.01, which NLB resistance QTL NLB_3.01 is located ina chromosomal interval flanked by any two of the marker loci selectedfrom the group consisting of SEQ ID NOs: 469 and 470.

In an aspect, a method provided herein comprises genotyping a cornplant, seed, or cell at a marker locus associated with NLB resistanceQTL NLB_9.01, which NLB resistance QTL NLB_9.01 is located in achromosomal interval flanked by any two of the marker loci selected fromthe group consisting of SEQ ID NOs: 85 to 89 and 476 to 482. In anotheraspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with NLB resistance QTLNLB_9.01, which NLB resistance QTL NLB_9.01 is located in a chromosomalinterval flanked by any two of the marker loci selected from the groupconsisting of SEQ ID NOs: 86 to 89, 476, 477, 479, and 480. In anotheraspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with NLB resistance QTLNLB_9.01, which NLB resistance QTL NLB_9.01 is located in a chromosomalinterval flanked by any two of the marker loci selected from the groupconsisting of SEQ ID NOs: 87 to 89, 477, and 480.

In an aspect, a method provided herein comprises genotyping a cornplant, seed, or cell at a marker locus associated with and within about20 cM of NLB resistance QTL NLB_9.01, which NLB resistance QTL NLB_9.01is located in a chromosomal interval flanked by any two of the markerloci selected from the group consisting of SEQ ID NOs: 85 to 89 and 476to 482. In an aspect, a method provided herein comprises genotyping acorn plant, seed, or cell at a marker locus associated with and withinabout 15 cM of NLB resistance QTL NLB_9.01, which NLB resistance QTLNLB_9.01 is located in a chromosomal interval flanked by any two of themarker loci selected from the group consisting of SEQ ID NOs: 85 to 89and 476 to 482. In an aspect, a method provided herein comprisesgenotyping a corn plant, seed, or cell at a marker locus associated withand within about 10 cM of NLB resistance QTL NLB_9.01, which NLBresistance QTL NLB_9.01 is located in a chromosomal interval flanked byany two of the marker loci selected from the group consisting of SEQ IDNOs: 85 to 89 and 476 to 482. In an aspect, a method provided hereincomprises genotyping a corn plant, seed, or cell at a marker locusassociated with and within about 5 cM of NLB resistance QTL NLB_9.01,which NLB resistance QTL NLB_9.01 is located in a chromosomal intervalflanked by any two of the marker loci selected from the group consistingof SEQ ID NOs: 85 to 89 and 476 to 482. In an aspect, a method providedherein comprises genotyping a corn plant, seed, or cell at a markerlocus associated with and within about 4 cM of NLB resistance QTLNLB_9.01, which NLB resistance QTL NLB_9.01 is located in a chromosomalinterval flanked by any two of the marker loci selected from the groupconsisting of SEQ ID NOs: 85 to 89 and 476 to 482. In an aspect, amethod provided herein comprises genotyping a corn plant, seed, or cellat a marker locus associated with and within about 3 cM of NLBresistance QTL NLB_9.01, which NLB resistance QTL NLB_9.01 is located ina chromosomal interval flanked by any two of the marker loci selectedfrom the group consisting of SEQ ID NOs: 85 to 89 and 476 to 482. In anaspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus associated with and within about 2 cM ofNLB resistance QTL NLB_9.01, which NLB resistance QTL NLB_9.01 islocated in a chromosomal interval flanked by any two of the marker lociselected from the group consisting of SEQ ID NOs: 85 to 89 and 476 to482. In an aspect, a method provided herein comprises genotyping a cornplant, seed, or cell at a marker locus associated with and within about1 cM of NLB resistance QTL NLB_9.01, which NLB resistance QTL NLB_9.01is located in a chromosomal interval flanked by any two of the markerloci selected from the group consisting of SEQ ID NOs: 85 to 89 and 476to 482. In an aspect, a method provided herein comprises genotyping acorn plant, seed, or cell at a marker locus associated with and withinabout 0.5 cM of NLB resistance QTL NLB_9.01, which NLB resistance QTLNLB_9.01 is located in a chromosomal interval flanked by any two of themarker loci selected from the group consisting of SEQ ID NOs: 85 to 89and 476 to 482. In an aspect, a method provided herein comprisesgenotyping a corn plant, seed, or cell at a marker locus within lessthan about 0.5 cM of NLB resistance QTL NLB_9.01, which NLB resistanceQTL NLB_3.01 is located in a chromosomal interval flanked by any two ofthe marker loci selected from the group consisting of SEQ ID NOs: 85 to89 and 476 to 482.

In a further aspect, a method provided herein comprises genotyping acorn plant, seed, or cell at a marker locus located in a chromosomalinterval flanked by any two of marker loci SEQ ID NOs: 1 to 18. Inanother aspect, a method provided herein comprises genotyping a cornplant, seed, or cell at a marker locus located in a chromosomal intervalflanked by any two of marker loci SEQ ID NOs: 12 to 15. In anotheraspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus located in a chromosomal intervalflanked by any two of marker loci SEQ ID NOs: 8 to 18.

In a further aspect, a method provided herein comprises genotyping acorn plant, seed, or cell at a marker locus located in a chromosomalinterval flanked by any two of marker loci SEQ ID NOs: 19 to 31. Inanother aspect, a method provided herein comprises genotyping a cornplant, seed, or cell at a marker locus located in a chromosomal intervalflanked by any two of marker loci SEQ ID NOs: 22 to 25. In anotheraspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus located in a chromosomal intervalflanked by any two of marker loci SEQ ID NOs: 21 to 29.

In a further aspect, a method provided herein comprises genotyping acorn plant, seed, or cell at a marker locus located in a chromosomalinterval flanked by any two of marker loci SEQ ID NOs: 32 to 52 and 471to 475. In another aspect, a method provided herein comprises genotypinga corn plant, seed, or cell at a marker locus located in a chromosomalinterval flanked by any two of marker loci SEQ ID NOs: 37 to 42 and 474.In yet another aspect, a method provided herein comprises genotyping acorn plant, seed, or cell at a marker locus located in a chromosomalinterval flanked by any two of marker loci SEQ ID NOs: 44 to 49. In yetanother aspect, a method provided herein comprises genotyping a cornplant, seed, or cell at a marker locus located in a chromosomal intervalflanked by any two of marker loci SEQ ID NOs: 33 to 42, 473, and 474. Inyet another aspect, a method provided herein comprises genotyping a cornplant, seed, or cell at a marker locus located in a chromosomal intervalflanked by any two of marker loci SEQ ID NOs: 43 to 49 and 475.

In a further aspect, a method provided herein comprises genotyping acorn plant, seed, or cell at a marker locus located in a chromosomalinterval flanked by any two of marker loci SEQ ID NOs: 53 to 65 and 446to 468. In another aspect, a method provided herein comprises genotypinga corn plant, seed, or cell at a marker locus located in a chromosomalinterval flanked by any two of marker loci SEQ ID NOs: 57 to 62 and 458to 466. In another aspect, a method provided herein comprises genotypinga corn plant, seed, or cell at a marker locus located in a chromosomalinterval flanked by any two of marker loci SEQ ID NOs: 57 to 64 and 458to 468.

In a further aspect, a method provided herein comprises genotyping acorn plant, seed, or cell at a marker locus located in a chromosomalinterval flanked by any two of marker loci SEQ ID NOs: 66 to 84. Inanother aspect, a method provided herein comprises genotyping a cornplant, seed, or cell at a marker locus located in a chromosomal intervalflanked by any two of marker loci SEQ ID NOs: 79 to 81. In anotheraspect, a method provided herein comprises genotyping a corn plant,seed, or cell at a marker locus located in a chromosomal intervalflanked by any two of marker loci SEQ ID NOs: 74 to 82.

In a further aspect, a method provided herein comprises genotyping acorn plant, seed, or cell at a marker locus located in a chromosomalinterval flanked by marker loci SEQ ID NOs: 469 and 470.

In a further aspect, a method provided herein comprises genotyping acorn plant, seed, or cell at a marker locus located in a chromosomalinterval flanked by any two of marker loci SEQ ID NOs: 85 to 89 and 476to 482. In another aspect, a method provided herein comprises genotypinga corn plant, seed, or cell at a marker locus located in a chromosomalinterval flanked by any two of marker loci SEQ ID NOs: 86 to 89, 476,477, 479, and 480. In another aspect, a method provided herein comprisesgenotyping a corn plant, seed, or cell at a marker locus located in achromosomal interval flanked by any two of marker loci SEQ ID NOs: 87 to89, 477, and 480.

In another aspect, a method provided herein comprises genotyping a cornplant, seed, or cell by detecting a haplotype. In an aspect, a haplotypecomprises an NLB resistance allele at one or more, two or more, three ormore, four or more, or five or more of marker loci SEQ ID NOs: 1 to 18.In an aspect, a haplotype comprises an NLB resistance allele at two ormore of marker loci SEQ ID NOs: 1 to 18. In an aspect, a haplotypecomprises an NLB resistance allele at three or more of marker loci SEQID NOs: 1 to 18. In an aspect, a haplotype comprises an NLB resistanceallele at four or more of marker loci SEQ ID NOs: 1 to 18. In an aspect,a haplotype comprises an NLB resistance allele at five or more of markerloci SEQ ID NOs: 1 to 18. In an aspect, a haplotype comprises an NLBresistance allele at one or more of marker loci SEQ ID NOs: 12 to 15. Inan aspect, a haplotype comprises an NLB resistance allele at two or moreof marker loci SEQ ID NOs: 12 to 15. In an aspect, a haplotype comprisesan NLB resistance allele at three or more of marker loci SEQ ID NOs: 12to 15. In an aspect, a haplotype comprises an NLB resistance allele atmarker loci SEQ ID NOs: 12 to 15. In an aspect, a haplotype comprises anNLB resistance allele at one or more of marker loci SEQ ID NO: 8 to 18.In an aspect, a haplotype comprises an NLB resistance allele at two ormore of marker loci SEQ ID NOs: 8 to 18. In an aspect, a haplotypecomprises an NLB resistance allele at three or more of marker loci SEQID NOs: 8 to 18. In an aspect, a haplotype comprises an NLB resistanceallele at four or more of marker loci SEQ ID NOs: 8 to 18. In an aspect,a haplotype comprises an NLB resistance allele at five or more of markerloci SEQ ID NOs: 8 to 18.

In an aspect, a haplotype comprises an NLB resistance allele at one ormore, two or more, three or more, four or more, or five or more ofmarker loci SEQ ID NOs: 19 to 31. In an aspect, a haplotype comprises anNLB resistance allele at two or more of marker loci SEQ ID NOs: 19 to31. In an aspect, a haplotype comprises an NLB resistance allele atthree or more of marker loci SEQ ID NOs: 19 to 31. In an aspect, ahaplotype comprises an NLB resistance allele at four or more of markerloci SEQ ID NOs: 19 to 31. In an aspect, a haplotype comprises an NLBresistance allele at five or more of marker loci SEQ ID NOs: 19 to 31.In an aspect, a haplotype comprises an NLB resistance allele at one ormore of marker loci SEQ ID NO: 22 to 25. In an aspect, a haplotypecomprises an NLB resistance allele at two or more of marker loci SEQ IDNOs: 22 to 25. In an aspect, a haplotype comprises an NLB resistanceallele at three or more of marker loci SEQ ID NOs: 22 to 25. In anaspect, a haplotype comprises an NLB resistance allele at marker lociSEQ ID NOs: 22 to 25. In an aspect, a haplotype comprises an NLBresistance allele at one or more of marker loci SEQ ID NO: 21 to 29. Inan aspect, a haplotype comprises an NLB resistance allele at two or moreof marker loci SEQ ID NOs: 21 to 29. In an aspect, a haplotype comprisesan NLB resistance allele at three or more of marker loci SEQ ID NOs: 21to 29. In an aspect, a haplotype comprises an NLB resistance allele atfour or more of marker loci SEQ ID NOs: 21 to 29. In an aspect, ahaplotype comprises an NLB resistance allele at five or more of markerloci SEQ ID NOs: 21 to 29.

In an aspect, a haplotype comprises an NLB resistance allele at one ormore of marker loci SEQ ID NO: 32 to 52 and 471 to 475. In an aspect, ahaplotype comprises an NLB resistance allele at two or more of markerloci SEQ ID NOs: 32 to 52 and 471 to 475. In an aspect, a haplotypecomprises an NLB resistance allele at three or more of marker loci SEQID NOs: 32 to 52 and 471 to 475. In an aspect, a haplotype comprises anNLB resistance allele at four or more of marker loci SEQ ID NOs: 32 to52 and 471 to 475. In an aspect, a haplotype comprises an NLB resistanceallele at five or more of marker loci SEQ ID NOs: 32 to 52 and 471 to475. In an aspect, a haplotype comprises an NLB resistance allele at oneor more of marker loci SEQ ID NO: 37 to 42 and 474. In an aspect, ahaplotype comprises an NLB resistance allele at two or more of markerloci SEQ ID NOs: 37 to 42 and 474. In an aspect, a haplotype comprisesan NLB resistance allele at three or more of marker loci SEQ ID NOs: 37to 42 and 474. In an aspect, a haplotype comprises an NLB resistanceallele at four or more of marker loci SEQ ID NOs: 37 to 42 and 474. Inan aspect, a haplotype comprises an NLB resistance allele at five ormore of marker loci SEQ ID NOs: 37 to 42 and 474. In an aspect, ahaplotype comprises an NLB resistance allele at one or more of markerloci SEQ ID NO: 33 to 42, 473 and 474. In an aspect, a haplotypecomprises an NLB resistance allele at two or more of marker loci SEQ IDNOs: 33 to 42, 473 and 474. In an aspect, a haplotype comprises an NLBresistance allele at three or more of marker loci SEQ ID NOs: 33 to 42,473 and 474. In an aspect, a haplotype comprises an NLB resistanceallele at four or more of marker loci SEQ ID NOs: 33 to 42, 473 and 474.In an aspect, a haplotype comprises an NLB resistance allele at five ormore of marker loci SEQ ID NOs: 33 to 42, 473 and 474. In an aspect, ahaplotype comprises an NLB resistance allele at one or more of markerloci SEQ ID NO: 43 to 49 and 475. In an aspect, a haplotype comprises anNLB resistance allele at two or more of marker loci SEQ ID NOs: 43 to 49and 475. In an aspect, a haplotype comprises an NLB resistance allele atthree or more of marker loci SEQ ID NOs: 43 to 49 and 475. In an aspect,a haplotype comprises an NLB resistance allele at four or more of markerloci SEQ ID NOs: 43 to 49 and 475. In an aspect, a haplotype comprisesan NLB resistance allele at five or more of marker loci SEQ ID NOs: 43to 49 and 475. In an aspect, a haplotype comprises an NLB resistanceallele at one or more of marker loci SEQ ID NO: 44 to 49. In an aspect,a haplotype comprises an NLB resistance allele at two or more of markerloci SEQ ID NOs: 44 to 49. In an aspect, a haplotype comprises an NLBresistance allele at three or more of marker loci SEQ ID NOs: 44 to 49.In an aspect, a haplotype comprises an NLB resistance allele at four ormore of marker loci SEQ ID NOs: 44 to 49. In an aspect, a haplotypecomprises an NLB resistance allele at five or more of marker loci SEQ IDNOs: 44 to 49.

In an aspect, a haplotype comprises an NLB resistance allele at one ormore of marker loci SEQ ID NO: 53 to 65 and 446 to 468. In an aspect, ahaplotype comprises an NLB resistance allele at two or more of markerloci SEQ ID NOs: 53 to 65 and 446 to 468. In an aspect, a haplotypecomprises an NLB resistance allele at three or more of marker loci SEQID NOs: 53 to 65 and 446 to 468. In an aspect, a haplotype comprises anNLB resistance allele at four or more of marker loci SEQ ID NOs: 53 to65 and 446 to 468. In an aspect, a haplotype comprises an NLB resistanceallele at five or more of marker loci SEQ ID NOs: 53 to 65 and 446 to468. In an aspect, a haplotype comprises an NLB resistance allele at oneor more of marker loci SEQ ID NO: 57 to 64 and 458 to 468. In an aspect,a haplotype comprises an NLB resistance allele at two or more of markerloci SEQ ID NOs: 57 to 64 and 458 to 468. In an aspect, a haplotypecomprises an NLB resistance allele at three or more of marker loci SEQID NOs: 57 to 64 and 458 to 468. In an aspect, a haplotype comprises anNLB resistance allele at four or more of marker loci SEQ ID NOs: 57 to64 and 458 to 468. In an aspect, a haplotype comprises an NLB resistanceallele at five or more of marker loci SEQ ID NOs: 57 to 64 and 458 to468. In an aspect, a haplotype comprises an NLB resistance allele at oneor more of marker loci SEQ ID NO: 57 to 62 and 458 to 466. In an aspect,a haplotype comprises an NLB resistance allele at two or more of markerloci SEQ ID NOs: 57 to 62 and 458 to 466. In an aspect, a haplotypecomprises an NLB resistance allele at three or more of marker loci SEQID NOs: 57 to 62 and 458 to 466. In an aspect, a haplotype comprises anNLB resistance allele at four or more of marker loci SEQ ID NOs: 57 to62 and 458 to 466. In an aspect, a haplotype comprises an NLB resistanceallele at five or more of marker loci SEQ ID NOs: 57 to 62 and 458 to466.

In an aspect, a haplotype comprises an NLB resistance allele at one ormore of marker loci SEQ ID NO: 66 to 84. In an aspect, a haplotypecomprises an NLB resistance allele at two or more of marker loci SEQ IDNOs: 66 to 84. In an aspect, a haplotype comprises an NLB resistanceallele at three or more of marker loci SEQ ID NOs: 66 to 84. In anaspect, a haplotype comprises an NLB resistance allele at four or moreof marker loci SEQ ID NOs: 66 to 84. In an aspect, a haplotype comprisesan NLB resistance allele at five or more of marker loci SEQ ID NOs: 66to 84. In an aspect, a haplotype comprises an NLB resistance allele atone or more of marker loci SEQ ID NO: 79 to 81. In an aspect, ahaplotype comprises an NLB resistance allele at two or more of markerloci SEQ ID NOs: 79 to 81. In an aspect, a haplotype comprises an NLBresistance allele at marker loci SEQ ID NOs: 79 to 81. In an aspect, ahaplotype comprises an NLB resistance allele at one or more of markerloci SEQ ID NO: 74 to 82. In an aspect, a haplotype comprises an NLBresistance allele at two or more of marker loci SEQ ID NOs: 74 to 82. Inan aspect, a haplotype comprises an NLB resistance allele at three ormore of marker loci SEQ ID NOs: 74 to 82. In an aspect, a haplotypecomprises an NLB resistance allele at four or more of marker loci SEQ IDNOs: 74 to 82. In an aspect, a haplotype comprises an NLB resistanceallele at five or more of marker loci SEQ ID NOs: 74 to 82.

In an aspect, a haplotype comprises an NLB resistance allele at one ormore of marker loci SEQ ID NO: 85 to 89 and 476 to 482. In an aspect, ahaplotype comprises an NLB resistance allele at two or more of markerloci SEQ ID NOs: 85 to 89 and 476 to 482. In an aspect, a haplotypecomprises an NLB resistance allele at three or more of marker loci SEQID NOs: 85 to 89 and 476 to 482. In an aspect, a haplotype comprises anNLB resistance allele at four or more of marker loci SEQ ID NOs: 85 to89 and 476 to 482. In an aspect, a haplotype comprises an NLB resistanceallele at five or more of marker loci SEQ ID NOs: 85 to 89 and 476 to482. In an aspect, a haplotype comprises an NLB resistance allele at oneor more of marker loci SEQ ID NO: 86 to 89, 476, 477, 479, and 480. Inan aspect, a haplotype comprises an NLB resistance allele at two or moreof marker loci SEQ ID NOs: 86 to 89, 476, 477, 479, and 480. In anaspect, a haplotype comprises an NLB resistance allele at three or moreof marker loci SEQ ID NOs: 86 to 89, 476, 477, 479, and 480. In anaspect, a haplotype comprises an NLB resistance allele at four or moreof marker loci SEQ ID NOs: 86 to 89, 476, 477, 479, and 480. In anaspect, a haplotype comprises an NLB resistance allele at five or moreof marker loci SEQ ID NOs: 86 to 89, 476, 477, 479, and 480. In anaspect, a haplotype comprises an NLB resistance allele at one or more,or two or more of marker loci SEQ ID NO: 87 to 89, 477 and 480. In anaspect, a haplotype comprises an NLB resistance allele at two or more ofmarker loci SEQ ID NOs: 87 to 89, 477 and 480. In an aspect, a haplotypecomprises an NLB resistance allele at three or more of marker loci SEQID NOs: 87 to 89, 477 and 480. In an aspect, a haplotype comprises anNLB resistance allele at four or more of marker loci SEQ ID NOs: 87 to89, 477 and 480. In an aspect, a haplotype comprises an NLB resistanceallele at five or more of marker loci SEQ ID NOs: 87 to 89, 477 and 480.

In an aspect, a haplotype comprises an NLB resistance allele at one ormore of marker loci SEQ ID NO: 469 and 470. In an aspect, a haplotypecomprises an NLB resistance allele at marker loci SEQ ID NO: 469 and470.

In an aspect, a corn plant, seed, or cell comprising NLB resistance QTLsor NLB resistant alleles provided herein exhibits intermediateresistance to NLB infection from Exserohilum turcicum (also referred toas Helminthosporium turcicum or Setosphaeria turcica). In anotheraspect, a corn plant, seed, or cell comprising NLB resistance QTLs orNLB resistant alleles provided herein exhibits at least mild resistance(e.g., NLB resistance score of <5; see Table 1) to NLB infection fromExserohilum turcicum (also referred to as Helminthosporium turcicum orSetosphaeria turcica). In a further aspect, a corn plant, seed, or cellcomprising NLB resistance QTLs or NLB resistant alleles provided hereinexhibits resistance (e.g., NLB resistance score of <4; see Table 1) toNLB infection from Exserohilum turcicum (also referred to asHelminthosporium turcicum or Setosphaeria turcica). In an aspect, NLBinfection is caused by Exserohilum turcicum (also referred to asHelminthosporium turcicum or Setosphaeria turcica).

As used herein, a “low NLB stress condition” refers to a condition wherevery few to no NLB susceptible corn plants in a field plot (e.g., lessthan 10%) exhibit signs of NLB infection. Signs of NLB infection caninclude: leaf lesions, foliage destruction, root rot, or stalk rot.

As used herein, a “high NLB stress condition” refers to a conditionwhere a plurality of NLB susceptible corn plants in a field plot (e.g.,more than 30%) exhibit signs of NLB infection.

As an example, an NLB resistance QTL or NLB resistance allele providedherein does not confer a yield penalty under a low NLB stress condition.In another example, a combination of two or more, three or more, four ormore, five or more, or six or more NLB resistance QTLs provided hereindoes not confer a yield penalty under a low NLB stress condition. In anaspect, presence of NLB resistance QTL NLB_2.01 in a corn plant, seed,or cell genome does not confer a yield penalty under a low NLB stresscondition. In an aspect, presence of NLB resistance QTL NLB_3.01 in acorn plant, seed, or cell genome does not confer a yield penalty under alow NLB stress condition. In an aspect, presence of NLB resistance QTLNLB_4.01 in a corn plant, seed, or cell genome does not confer a yieldpenalty under a low NLB stress condition. In an aspect, presence of NLBresistance QTL NLB_4.02 in a corn plant, seed, or cell genome does notconfer a yield penalty under a low NLB stress condition. In an aspect,presence of NLB resistance QTL NLB_5.01 in a corn plant, seed, or cellgenome does not confer a yield penalty under a low NLB stress condition.In an aspect, presence of NLB resistance QTL NLB_6.01 in a corn plant,seed, or cell genome does not confer a yield penalty under a low NLBstress condition. In an aspect, presence of NLB resistance QTL NLB_7.01in a corn plant, seed, or cell genome does not confer a yield penaltyunder a low NLB stress condition. In an aspect, presence of NLBresistance QTL NLB_9.01 in a corn plant, seed, or cell genome does notconfer a yield penalty under a low NLB stress condition.

In another aspect, a corn plant or seed provided herein comprising oneor more, two or more, three or more, four or more, five or more, six ormore, or seven or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01 exhibits areduction of NLB rating score of about 0.25 or more, 0.5 or more, 0.75or more, 1 or more, 1.5 or more, 2 or more, 2.5 or more, 3 or more, 3.5or more, 4 or more, 4.5 or more, 5 or more, 5.5 or more, 6 or more, 6.5or more, 7 or more, or 7.5 or more compared to a corn plant or seedwithout the one or more, two or more, three or more, four or more, fiveor more, or six or more NLB resistance QTLs under a high NLB stresscondition.

In an aspect, a corn plant or seed provided herein as described in anyof paragraphs [00175] to [00183] exhibits a reduction of NLB ratingscore of about 0.25 or more compared to a corn plant without the one ormore, two or more, three or more, four or more, five or more, six ormore, or seven or more NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a reductionof NLB rating score of about 0.5 or more compared to a corn plantwithout the one or more, two or more, three or more, four or more, fiveor more, six or more, or seven or more NLB resistance QTLs under a highNLB stress condition. In an aspect, a corn plant or seed provided hereinas described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of about 0.75 or more compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of about 1 or more compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of about 1.5 or more compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of about 2 or more compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of about 2.5 or more compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of about 3 or more compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of about 3.5 or more compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of about 4 or more compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of about 4.5 or more compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of about 5 or more compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of about 5.5 or more compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of about 6 or more compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of about 6.5 or more compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of about 7 or more compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of about 7.5 or more compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition.

In another aspect, a corn plant or seed provided herein comprising oneor more, two or more, three or more, four or more, five or more, six ormore, or seven or more NLB resistance QTLs or NLB resistance allelesprovided herein exhibits a reduction of NLB rating score of about 0.25or more, 0.5 or more, 0.75 or more, 1 or more, 1.5 or more, 2 or more,2.5 or more, 3 or more, 3.5 or more, 4 or more, 4.5 or more, 5 or more,5.5 or more, 6 or more, 6.5 or more, 7 or more, or 7.5 or more comparedto a corn plant or seed without the one or more, two or more, three ormore, four or more, five or more, or six or more NLB resistance QTLs orNLB resistance alleles under a high NLB stress condition.

In another aspect, a corn plant or seed provided herein comprising oneor more, two or more, three or more, four or more, five or more, six ormore, or seven or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01 exhibits areduction of NLB rating score of between 0.25 and 8, between 0.25 and7.5, between 0.25 and 7, between 0.25 and 6.5, between 0.25 and 6,between 0.25 and 5.5, between 0.25 and 5, between 0.25 and 4.5, between0.25 and 4, between 0.25 and 3.5, between 0.25 and 3, between 0.25 and2.5, between 0.25 and 2, between 0.25 and 1.5, between 0.25 and 1,between 1 and 8, between 1 and 7, between 1 and 6, between 1 and 5,between 1 and 4, between 1 and 3, or between 1 and 2 compared to a cornplant or seed without the one or more, two or more, three or more, fouror more, five or more, six or more, or seven or more NLB resistance QTLsunder a high NLB stress condition.

In an aspect, a corn plant or seed provided herein as described in anyof paragraphs [00175] to [00183] exhibits a reduction of NLB ratingscore of between 0.25 and 8 compared to a corn plant without the one ormore, two or more, three or more, four or more, five or more, six ormore, or seven or more NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a reductionof NLB rating score of between 0.25 and 7.5 compared to a corn plantwithout the one or more, two or more, three or more, four or more, fiveor more, six or more, or seven or more NLB resistance QTLs under a highNLB stress condition. In an aspect, a corn plant or seed provided hereinas described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of between 0.25 and 7 compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of between 0.25 and 6.5 compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of between 0.25 and 6 compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of between 0.25 and 5.5 compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of between 0.25 and 5 compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of between 0.25 and 4.5 compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of between 0.25 and 4 compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of between 0.25 and 3.5 compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of between 0.25 and 3 compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of between 0.25 and 2.5 compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of between 0.25 and 2 compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of between 0.25 and 1.5 compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of between 0.25 and 1 compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of between 1 and 8 compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of between 1 and 7 compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of between 1 and 6 compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of between 1 and 5 compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of between 1 and 4 compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of between 1 and 3 compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits areduction of NLB rating score of between 1 and 2 compared to a cornplant without the one or more, two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs under ahigh NLB stress condition.

In another aspect, a corn plant or seed provided herein comprising oneor more, two or more, three or more, four or more, five or more, six ormore, or seven or more NLB resistance QTLs or NLB resistance allelesprovided herein exhibits a reduction of NLB rating score of between 0.25and 8, between 0.25 and 7.5, between 0.25 and 7, between 0.25 and 6.5,between 0.25 and 6, between 0.25 and 5.5, between 0.25 and 5, between0.25 and 4.5, between 0.25 and 4, between 0.25 and 3.5, between 0.25 and3, between 0.25 and 2.5, between 0.25 and 2, between 0.25 and 1.5,between 0.25 and 1, between 1 and 8, between 1 and 7, between 1 and 6,between 1 and 5, between 1 and 4, between 1 and 3, or between 1 and 2compared to a corn plant or seed without the one or more, two or more,three or more, four or more, five or more, six or more, or seven or moreNLB resistance QTLs or NLB resistance alleles under a high NLB stresscondition.

In another aspect, a corn plant or seed provided herein comprising oneor more, two or more, three or more, four or more, five or more, six ormore, or seven or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01 exhibits areduction of NLB rating score of between 5% and 90%, 5% and 80%, between5% and 70%, between 5% and 60%, between 5% and 50%, between 5% and 40%,between 5% and 30%, between 5% and 20%, between 5% and 15%, or between5% and 10%, compared to a corn plant or seed without the one or more,two or more, three or more, four or more, five or more, six or more, orseven or more NLB resistance QTLs under a high NLB stress condition.

In an aspect, a corn plant or seed provided herein comprising one ormore, two or more, three or more, four or more, five or more, six ormore, seven or more, eight or more, nine or more, ten or more, or elevenor more NLB resistance QTLs or NLB resistance alleles provided hereinexhibits a seed yield increase of about 1% or more, 2% or more, 3% ormore, 4% or more, 5% or more, 10% or more, 15% or more, 20% or more, 25%or more, 30% or more, 40% or more, 50% or more, 60% or more, 70% ormore, 80% or more, 90% or more, or 100% or more than seed yield of acorn plant or seed without the one or more, two or more, three or more,four or more, five or more, six or more, seven or more, eight or more,nine or more, ten or more, or eleven or more NLB resistance QTLs or NLBresistance alleles under a high NLB stress condition.

In an aspect, a corn plant or seed provided herein as described in anyof paragraphs [00175] to [00183] exhibits a seed yield increase of about1% or more than seed yield of a corn plant or seed without the NLBresistance QTLs under a high NLB stress condition. In an aspect, a cornplant or seed provided herein comprising one or more, two or more, threeor more, four or more, five or more, six or more, seven or more, eightor more, nine or more, ten or more, or eleven or more NLB resistancealleles provided herein exhibits a seed yield increase of about 1% ormore than seed yield of a corn plant or seed without the one or more,two or more, three or more, four or more, five or more, six or more,seven or more, eight or more, nine or more, ten or more, or eleven ormore NLB resistance alleles under a high NLB stress condition.

In an aspect, a corn plant or seed provided herein as described in anyof paragraphs [00175] to [00183] exhibits a seed yield increase of about2% or more than seed yield of a corn plant or seed without the NLBresistance QTLs under a high NLB stress condition. In an aspect, a cornplant or seed provided herein comprising one or more, two or more, threeor more, four or more, five or more, six or more, seven or more, eightor more, nine or more, ten or more, or eleven or more NLB resistancealleles provided herein exhibits a seed yield increase of about 2% ormore than seed yield of a corn plant or seed without the one or more,two or more, three or more, four or more, five or more, six or more,seven or more, eight or more, nine or more, ten or more, or eleven ormore NLB resistance alleles under a high NLB stress condition.

In an aspect, a corn plant or seed provided herein as described in anyof paragraphs [00175] to [00183] exhibits a seed yield increase of about3% or more than seed yield of a corn plant or seed without the NLBresistance QTLs under a high NLB stress condition. In an aspect, a cornplant or seed provided herein comprising one or more, two or more, threeor more, four or more, five or more, six or more, seven or more, eightor more, nine or more, ten or more, or eleven or more NLB resistancealleles provided herein exhibits a seed yield increase of about 3% ormore than seed yield of a corn plant or seed without the one or more,two or more, three or more, four or more, five or more, six or more,seven or more, eight or more, nine or more, ten or more, or eleven ormore NLB resistance alleles under a high NLB stress condition.

In an aspect, a corn plant or seed provided herein as described in anyof paragraphs [00175] to [00183] exhibits a seed yield increase of about4% or more than seed yield of a corn plant or seed without the NLBresistance QTLs under a high NLB stress condition. In an aspect, a cornplant or seed provided herein comprising one or more, two or more, threeor more, four or more, five or more, six or more, seven or more, eightor more, nine or more, ten or more, or eleven or more NLB resistancealleles provided herein exhibits a seed yield increase of about 4% ormore than seed yield of a corn plant or seed without the one or more,two or more, three or more, four or more, five or more, six or more,seven or more, eight or more, nine or more, ten or more, or eleven ormore NLB resistance alleles under a high NLB stress condition.

In an aspect, a corn plant or seed provided herein as described in anyof paragraphs [00175] to [00183] exhibits a seed yield increase of about5% or more than seed yield of a corn plant or seed without the NLBresistance QTLs under a high NLB stress condition. In an aspect, a cornplant or seed provided herein comprising one or more, two or more, threeor more, four or more, five or more, six or more, seven or more, eightor more, nine or more, ten or more, or eleven or more NLB resistancealleles provided herein exhibits a seed yield increase of about 5% ormore than seed yield of a corn plant or seed without the one or more,two or more, three or more, four or more, five or more, six or more,seven or more, eight or more, nine or more, ten or more, or eleven ormore NLB resistance alleles under a high NLB stress condition.

In an aspect, a corn plant or seed provided herein as described in anyof paragraphs [00175] to [00183] exhibits a seed yield increase of about10% or more than seed yield of a corn plant or seed without the NLBresistance QTLs under a high NLB stress condition. In an aspect, a cornplant or seed provided herein comprising one or more, two or more, threeor more, four or more, five or more, six or more, seven or more, eightor more, nine or more, ten or more, or eleven or more NLB resistancealleles provided herein exhibits a seed yield increase of about 10% ormore than seed yield of a corn plant or seed without the one or more,two or more, three or more, four or more, five or more, six or more,seven or more, eight or more, nine or more, ten or more, or eleven ormore NLB resistance alleles under a high NLB stress condition.

In an aspect, a corn plant or seed provided herein as described in anyof paragraphs [00175] to [00183] exhibits a seed yield increase of about15% or more than seed yield of a corn plant or seed without the NLBresistance QTLs under a high NLB stress condition. In an aspect, a cornplant or seed provided herein comprising one or more, two or more, threeor more, four or more, five or more, six or more, seven or more, eightor more, nine or more, ten or more, or eleven or more NLB resistancealleles provided herein exhibits a seed yield increase of about 15% ormore than seed yield of a corn plant or seed without the one or more,two or more, three or more, four or more, five or more, six or more,seven or more, eight or more, nine or more, ten or more, or eleven ormore NLB resistance alleles under a high NLB stress condition.

In an aspect, a corn plant or seed provided herein as described in anyof paragraphs [00175] to [00183] exhibits a seed yield increase of about20% or more than seed yield of a corn plant or seed without the NLBresistance QTLs under a high NLB stress condition. In an aspect, a cornplant or seed provided herein comprising one or more, two or more, threeor more, four or more, five or more, six or more, seven or more, eightor more, nine or more, ten or more, or eleven or more NLB resistancealleles provided herein exhibits a seed yield increase of about 20% ormore than seed yield of a corn plant or seed without the one or more,two or more, three or more, four or more, five or more, six or more,seven or more, eight or more, nine or more, ten or more, or eleven ormore NLB resistance alleles under a high NLB stress condition.

In an aspect, a corn plant or seed provided herein as described in anyof paragraphs [00175] to [00183] exhibits a seed yield increase of about25% or more than seed yield of a corn plant or seed without the NLBresistance QTLs under a high NLB stress condition. In an aspect, a cornplant or seed provided herein comprising one or more, two or more, threeor more, four or more, five or more, six or more, seven or more, eightor more, nine or more, ten or more, or eleven or more NLB resistancealleles provided herein exhibits a seed yield increase of about 25% ormore than seed yield of a corn plant or seed without the one or more,two or more, three or more, four or more, five or more, six or more,seven or more, eight or more, nine or more, ten or more, or eleven ormore NLB resistance alleles under a high NLB stress condition.

In an aspect, a corn plant or seed provided herein as described in anyof paragraphs [00175] to [00183] exhibits a seed yield increase of about30% or more than seed yield of a corn plant or seed without the NLBresistance QTLs under a high NLB stress condition. In an aspect, a cornplant or seed provided herein comprising one or more, two or more, threeor more, four or more, five or more, six or more, seven or more, eightor more, nine or more, ten or more, or eleven or more NLB resistancealleles provided herein exhibits a seed yield increase of about 30% ormore than seed yield of a corn plant or seed without the one or more,two or more, three or more, four or more, five or more, six or more,seven or more, eight or more, nine or more, ten or more, or eleven ormore NLB resistance alleles under a high NLB stress condition.

In an aspect, a corn plant or seed provided herein as described in anyof paragraphs [00175] to [00183] exhibits a seed yield increase of about40% or more than seed yield of a corn plant or seed without the NLBresistance QTLs under a high NLB stress condition. In an aspect, a cornplant or seed provided herein comprising one or more, two or more, threeor more, four or more, five or more, six or more, seven or more, eightor more, nine or more, ten or more, or eleven or more NLB resistancealleles provided herein exhibits a seed yield increase of about 40% ormore than seed yield of a corn plant or seed without the one or more,two or more, three or more, four or more, five or more, six or more,seven or more, eight or more, nine or more, ten or more, or eleven ormore NLB resistance alleles under a high NLB stress condition.

In an aspect, a corn plant or seed provided herein as described in anyof paragraphs [00175] to [00183] exhibits a seed yield increase of about50% or more than seed yield of a corn plant or seed without the NLBresistance QTLs under a high NLB stress condition. In an aspect, a cornplant or seed provided herein comprising one or more, two or more, threeor more, four or more, five or more, six or more, seven or more, eightor more, nine or more, ten or more, or eleven or more NLB resistancealleles provided herein exhibits a seed yield increase of about 50% ormore than seed yield of a corn plant or seed without the one or more,two or more, three or more, four or more, five or more, six or more,seven or more, eight or more, nine or more, ten or more, or eleven ormore NLB resistance alleles under a high NLB stress condition.

In an aspect, a corn plant or seed provided herein as described in anyof paragraphs [00175] to [00183] exhibits a seed yield increase of about60% or more than seed yield of a corn plant or seed without the NLBresistance QTLs under a high NLB stress condition. In an aspect, a cornplant or seed provided herein comprising one or more, two or more, threeor more, four or more, five or more, six or more, seven or more, eightor more, nine or more, ten or more, or eleven or more NLB resistancealleles provided herein exhibits a seed yield increase of about 60% ormore than seed yield of a corn plant or seed without the one or more,two or more, three or more, four or more, five or more, six or more,seven or more, eight or more, nine or more, ten or more, or eleven ormore NLB resistance alleles under a high NLB stress condition.

In an aspect, a corn plant or seed provided herein as described in anyof paragraphs [00175] to [00183] exhibits a seed yield increase of about70% or more than seed yield of a corn plant or seed without the NLBresistance QTLs under a high NLB stress condition. In an aspect, a cornplant or seed provided herein comprising one or more, two or more, threeor more, four or more, five or more, six or more, seven or more, eightor more, nine or more, ten or more, or eleven or more NLB resistancealleles provided herein exhibits a seed yield increase of about 70% ormore than seed yield of a corn plant or seed without the one or more,two or more, three or more, four or more, five or more, six or more,seven or more, eight or more, nine or more, ten or more, or eleven ormore NLB resistance alleles under a high NLB stress condition.

In an aspect, a corn plant or seed provided herein as described in anyof paragraphs [00175] to [00183] exhibits a seed yield increase of about80% or more than seed yield of a corn plant or seed without the NLBresistance QTLs under a high NLB stress condition. In an aspect, a cornplant or seed provided herein comprising one or more, two or more, threeor more, four or more, five or more, six or more, seven or more, eightor more, nine or more, ten or more, or eleven or more NLB resistancealleles provided herein exhibits a seed yield increase of about 80% ormore than seed yield of a corn plant or seed without the one or more,two or more, three or more, four or more, five or more, six or more,seven or more, eight or more, nine or more, ten or more, or eleven ormore NLB resistance alleles under a high NLB stress condition.

In an aspect, a corn plant or seed provided herein as described in anyof paragraphs [00175] to [00183] exhibits a seed yield increase of about90% or more than seed yield of a corn plant or seed without the NLBresistance QTLs under a high NLB stress condition. In an aspect, a cornplant or seed provided herein comprising one or more, two or more, threeor more, four or more, five or more, six or more, seven or more, eightor more, nine or more, ten or more, or eleven or more NLB resistancealleles provided herein exhibits a seed yield increase of about 90% ormore than seed yield of a corn plant or seed without the one or more,two or more, three or more, four or more, five or more, six or more,seven or more, eight or more, nine or more, ten or more, or eleven ormore NLB resistance alleles under a high NLB stress condition.

In an aspect, a corn plant or seed provided herein as described in anyof paragraphs [00175] to [00183] exhibits a seed yield increase of about100% or more than seed yield of a corn plant or seed without the NLBresistance QTLs under a high NLB stress condition. In an aspect, a cornplant or seed provided herein comprising one or more, two or more, threeor more, four or more, five or more, six or more, seven or more, eightor more, nine or more, ten or more, or eleven or more NLB resistancealleles provided herein exhibits a seed yield increase of about 100% ormore than seed yield of a corn plant or seed without the one or more,two or more, three or more, four or more, five or more, six or more,seven or more, eight or more, nine or more, ten or more, or eleven ormore NLB resistance alleles under a high NLB stress condition.

In an aspect, a corn plant or seed provided herein comprising one ormore, two or more, three or more, four or more, five or more, six ormore, or seven or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01 exhibits a seedyield increase of about 1% or more, 2% or more, 3% or more, 4% or more,5% or more, 10% or more, 15% or more, 20% or more, 25% or more, 30% ormore, 40% or more, 50% or more, 60% or more, 70% or more, 80% or more,90% or more, or 100% or more than seed yield of a corn plant or seedwithout the one or more, two or more, three or more, four or more, fiveor more, six or more, or seven or more NLB resistance QTLs under a highNLB stress condition.

In another aspect, a corn plant or seed provided herein comprising oneor more, two or more, three or more, four or more, five or more, six ormore, or seven or more NLB resistance QTLs or NLB resistance allelesprovided herein exhibits a seed yield increase of between 1% and 100%,between 1% and 90%, between 1% and 80%, between 1% and 70%, between 1%and 60%, between 1% and 50%, between 1% and 40%, between 1% and 30%,between 1% and 25%, between 1% and 20%, between 1% and 15%, between 1%and 10%, between 1% and 5%, between 1% and 4%, between 1% and 3%,between 1% and 2%, between 2% and 90%, between 3% and 80%, between 4%and 70%, between 5% and 60%, between 10% and 50%, between 15% and 40%,between 20% and 30%, or between 5% and 25% of seed yield of a corn plantor seed without the one or more, two or more, three or more, four ormore, five or more, six or more, or seven or more NLB resistance QTLs orNLB resistance alleles under a high NLB stress condition.

In an aspect, a corn plant or seed provided herein comprising one ormore, two or more, three or more, four or more, five or more, six ormore, or seven or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01 exhibits a seedyield increase of between 1% and 100%, between 1% and 90%, between 1%and 80%, between 1% and 70%, between 1% and 60%, between 1% and 50%,between 1% and 40%, between 1% and 30%, between 1% and 25%, between 1%and 20%, between 1% and 15%, between 1% and 10%, between 1% and 5%,between 1% and 4%, between 1% and 3%, between 1% and 2%, between 2% and90%, between 3% and 80%, between 4% and 70%, between 5% and 60%, between10% and 50%, between 15% and 40%, between 20% and 30%, or between 5% and25% of seed yield of a corn plant or seed without the one or more, twoor more, three or more, four or more, five or more, six or more, orseven or more NLB resistance QTLs under a high NLB stress condition. Inan aspect, a corn plant or seed provided herein as described in any ofparagraphs [00175] to [00183] exhibits a seed yield increase of between1% and 100% compared to the seed yield of a corn plant or seed withoutthe NLB resistance QTLs under a high NLB stress condition. In an aspect,a corn plant or seed provided herein as described in any of paragraphs[00175] to [00183] exhibits a seed yield increase of between 1% and 90%compared to the seed yield of a corn plant or seed without the NLBresistance QTLs under a high NLB stress condition. In an aspect, a cornplant or seed provided herein as described in any of paragraphs [00175]to [00183] exhibits a seed yield increase of between 1% and 80% comparedto the seed yield of a corn plant or seed without the NLB resistanceQTLs under a high NLB stress condition. In an aspect, a corn plant orseed provided herein as described in any of paragraphs [00175] to[00183] exhibits a seed yield increase of between 1% and 70% compared tothe seed yield of a corn plant or seed without the NLB resistance QTLsunder a high NLB stress condition. In an aspect, a corn plant or seedprovided herein as described in any of paragraphs [00175] to [00183]exhibits a seed yield increase of between 1% and 60% compared to theseed yield of a corn plant or seed without the NLB resistance QTLs undera high NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits aseed yield increase of between 1% and 50% compared to the seed yield ofa corn plant or seed without the NLB resistance QTLs under a high NLBstress condition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of between 1% and 40% compared to the seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of between 1% and 30% compared to the seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of between 1% and 25% compared to the seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of between 1% and 20% compared to the seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of between 1% and 15% compared to the seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of between 1% and 10% compared to the seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of between 1% and 5% compared to the seed yield of a corn plantor seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of between 1% and 4% compared to the seed yield of a corn plantor seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of between 1% and 3% compared to the seed yield of a corn plantor seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of between 1% and 2% compared to the seed yield of a corn plantor seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of between 2% and 90% compared to the seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of between 3% and 80% compared to the seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of between 4% and 70% compared to the seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of between 5% and 60% compared to the seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of between 10% and 50% compared to the seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of between 15% and 40% compared to the seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of between 20% and 30% compared to the seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of between 5% and 25% compared to the seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition.

In an aspect, a corn plant or seed provided herein comprising one ormore, two or more, three or more, four or more, five or more, six ormore, or seven or more NLB resistance QTLs or NLB resistance allelesprovided herein exhibits a seed yield about 0.1 quintal/hectare or more,0.25 quintal/hectare or more, 0.5 quintal/hectare or more, 0.75quintal/hectare or more, 1 quintal/hectare or more, 1.5 quintal/hectareor more, 2 quintal/hectare or more, 2.5 quintal/hectare or more, 3quintal/hectare or more, 3.5 quintal/hectare or more, 4 quintal/hectareor more, 4.5 quintal/hectare or more, 5 quintal/hectare or more, 6quintal/hectare or more, 7 quintal/hectare or more, 8 quintal/hectare ormore, 9 quintal/hectare or more, or 10 quintal/hectare or more higherthan seed yield of a corn plant or seed without the one or more, two ormore, three or more, four or more, five or more, six or more, or sevenor more NLB resistance QTLs or NLB resistance alleles under a high NLBstress condition.

In an aspect, a corn plant or seed provided herein comprising one ormore, two or more, three or more, four or more, five or more, six ormore, or seven or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01 exhibits a seedyield about 0.1 quintal/hectare or more, 0.25 quintal/hectare or more,0.5 quintal/hectare or more, 0.75 quintal/hectare or more, 1quintal/hectare or more, 1.5 quintal/hectare or more, 2 quintal/hectareor more, 2.5 quintal/hectare or more, 3 quintal/hectare or more, 3.5quintal/hectare or more, 4 quintal/hectare or more, 4.5 quintal/hectareor more, 5 quintal/hectare or more, 6 quintal/hectare or more, 7quintal/hectare or more, 8 quintal/hectare or more, 9 quintal/hectare ormore, or 10 quintal/hectare or more higher than seed yield of a cornplant or seed without the one or more, two or more, three or more, fouror more, five or more, six or more, or seven or more NLB resistance QTLsunder a high NLB stress condition. In an aspect, a corn plant or seedprovided herein as described in any of paragraphs [00175] to [00183]exhibits a seed yield increase of about 0.1 quintal/hectare or more thanseed yield of a corn plant or seed without the NLB resistance QTLs undera high NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits aseed yield increase of about 0.25 quintal/hectare or more than seedyield of a corn plant or seed without the NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits aseed yield increase of about 0.5 quintal/hectare or more than seed yieldof a corn plant or seed without the NLB resistance QTLs under a high NLBstress condition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of about 0.75 quintal/hectare or more than seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of about 1 quintal/hectare or more than seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of about 1.5 quintal/hectare or more than seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of about 2 quintal/hectare or more than seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of about 2.5 quintal/hectare or more than seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of about 3 quintal/hectare or more than seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of about 0.1 quintal/hectare or more than seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of about 4 quintal/hectare or more than seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of about 4.5 quintal/hectare or more than seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of about 5 quintal/hectare or more than seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of about 6 quintal/hectare or more than seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of about 7 quintal/hectare or more than seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of about 8 quintal/hectare or more than seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of about 9 quintal/hectare or more than seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldincrease of about 10 quintal/hectare or more than seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition.

In another aspect, a corn plant or seed provided herein comprising oneor more, two or more, three or more, four or more, five or more, six ormore, or seven or more NLB resistance QTLs or NLB resistance allelesprovided herein exhibits a seed yield between 0.1 and 10quintal/hectare, between 0.1 and 9 quintal/hectare, between 0.1 and 8quintal/hectare, between 0.1 and 7 quintal/hectare, between 0.1 and 6quintal/hectare, between 0.1 and 5 quintal/hectare, between 0.1 and 4.5quintal/hectare, between 0.1 and 4 quintal/hectare, between 0.1 and 3.5quintal/hectare, between 0.1 and 3 quintal/hectare, between 0.1 and 2.5quintal/hectare, between 0.1 and 2 quintal/hectare, between 0.1 and 1.5quintal/hectare, between 0.1 and 1 quintal/hectare, between 0.1 and 0.75quintal/hectare, between 0.1 and 0.5 quintal/hectare, between 0.1 and0.25 quintal/hectare, between 0.25 and 9 quintal/hectare, between 0.5and 8 quintal/hectare, between 0.75 and 7 quintal/hectare, between 1 and6 quintal/hectare, between 1.5 and 5 quintal/hectare, between 2 and 4.5quintal/hectare, between 2.5 and 4 quintal/hectare, or between 3 and 3.5quintal/hectare higher than seed yield of a corn plant or seed withoutthe one or more, two or more, three or more, four or more, five or more,six or more, or seven or more NLB resistance QTLs or NLB resistancealleles under a high NLB stress condition. In an aspect, a corn plant orseed provided herein as described in any of paragraphs [00175] to[00183] exhibits a seed yield between 0.1 and 10 quintal/hectare higherthan seed yield of a corn plant or seed without the NLB resistance QTLsunder a high NLB stress condition. In an aspect, a corn plant or seedprovided herein as described in any of paragraphs [00175] to [00183]exhibits a seed yield between 0.1 and 9 quintal/hectare higher than seedyield of a corn plant or seed without the NLB resistance QTLs under ahigh NLB stress condition. In an aspect, a corn plant or seed providedherein as described in any of paragraphs [00175] to [00183] exhibits aseed yield between 0.1 and 8 quintal/hectare higher than seed yield of acorn plant or seed without the NLB resistance QTLs under a high NLBstress condition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldbetween 0.1 and 7 quintal/hectare higher than seed yield of a corn plantor seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldbetween 0.1 and 6 quintal/hectare higher than seed yield of a corn plantor seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldbetween 0.1 and 5 quintal/hectare higher than seed yield of a corn plantor seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldbetween 0.1 and 4.5 quintal/hectare higher than seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldbetween 0.1 and 4 quintal/hectare higher than seed yield of a corn plantor seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldbetween 0.1 and 3.5 quintal/hectare higher than seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldbetween 0.1 and 3 quintal/hectare higher than seed yield of a corn plantor seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldbetween 0.1 and 2.5 quintal/hectare higher than seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldbetween 0.1 and 2 quintal/hectare higher than seed yield of a corn plantor seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldbetween 0.1 and 1.5 quintal/hectare higher than seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldbetween 0.1 and 1 quintal/hectare higher than seed yield of a corn plantor seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldbetween 0.1 and 0.75 quintal/hectare higher than seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldbetween 0.1 and 0.5 quintal/hectare higher than seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldbetween 0.1 and 0.25 quintal/hectare higher than seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldbetween 0.25 and 9 quintal/hectare higher than seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldbetween 0.5 and 8 quintal/hectare higher than seed yield of a corn plantor seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldbetween 0.75 and 7 quintal/hectare higher than seed yield of a cornplant or seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldbetween 1 and 6 quintal/hectare higher than seed yield of a corn plantor seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldbetween 1.5 and 5 quintal/hectare higher than seed yield of a corn plantor seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldbetween 2 and 4 quintal/hectare higher than seed yield of a corn plantor seed without the NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed provided herein asdescribed in any of paragraphs [00175] to [00183] exhibits a seed yieldbetween 3 and 3.5 quintal/hectare higher than seed yield of a corn plantor seed without the NLB resistance QTLs under a high NLB stresscondition.

In an aspect, a corn plant or seed provided herein comprising one ormore, two or more, three or more, four or more, five or more, six ormore, or seven or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_7.01, NLB_6.01, and NLB_9.01 exhibits a seedyield between 0.1 and 10 quintal/hectare, between 0.1 and 9quintal/hectare, between 0.1 and 8 quintal/hectare, between 0.1 and 7quintal/hectare, between 0.1 and 6 quintal/hectare, between 0.1 and 5quintal/hectare, between 0.1 and 4.5 quintal/hectare, between 0.1 and 4quintal/hectare, between 0.1 and 3.5 quintal/hectare, between 0.1 and 3quintal/hectare, between 0.1 and 2.5 quintal/hectare, between 0.1 and 2quintal/hectare, between 0.1 and 1.5 quintal/hectare, between 0.1 and 1quintal/hectare, between 0.1 and 0.75 quintal/hectare, between 0.1 and0.5 quintal/hectare, between 0.1 and 0.25 quintal/hectare, between 0.25and 9 quintal/hectare, between 0.5 and 8 quintal/hectare, between 0.75and 7 quintal/hectare, between 1 and 6 quintal/hectare, between 1.5 and5 quintal/hectare, between 2 and 4.5 quintal/hectare, between 2.5 and 4quintal/hectare, or between 3 and 3.5 quintal/hectare higher than seedyield of a corn plant or seed without the one or more, two or more,three or more, four or more, five or more, six or more, or seven or moreNLB resistance QTLs under a high NLB stress condition.

In an aspect, this disclosure provides an NLB resistant corn plant orseed comprising one or more, two or more, three or more, four or more,five or more, six or more, or seven or more introgressed NLB resistanceQTLs selected from the group consisting of NLB resistance QTLs NLB_2.01,NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, andNLB_9.01. In an aspect, a corn plant or seed provided herein comprisesNLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01,NLB_6.01, NLB_7.01, and NLB_9.01 obtainable, obtained, or introgressedfrom any one of corn lines CV114258, CV115214, CV099829, CV102084,CV095508, CV103141, CV105893, CV595358, CV593417, CV117407, CV592505,and CV592420.

In an aspect, a corn plant, seed, or cell provided herein comprises NLBresistance QTLs NLB_4.01, and NLB_4.02. In another aspect, a corn plant,seed, or cell provided herein comprises NLB resistance QTLs NLB_2.01,NLB_4.01, and NLB_4.02. In an aspect, a corn plant, seed, or cellprovided herein comprises NLB resistance QTLs NLB_2.01 and NLB_4.01. Inan aspect, a corn plant, seed, or cell provided herein comprises NLBresistance QTLs NLB_2.01 and NLB_4.02.

In another aspect, a corn plant, seed, or cell provided herein comprisesNLB resistance QTL NLB_2.01 and one or more NLB resistance QTLs selectedfrom the group consisting of NLB resistance QTLs NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect,a corn plant, seed, or cell provided herein comprises NLB resistance QTLNLB_2.01 and two or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_3.01, NLB_4.01, NLB_4.02,NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_2.01 and three or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_3.01, NLB_4.01, NLB_4.02,NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_2.01 and four or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_3.01, NLB_4.01, NLB_4.02,NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_2.01 and five or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_3.01, NLB_4.01, NLB_4.02,NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_2.01 and or six or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_3.01, NLB_4.01, NLB_4.02,NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_2.01 and NLB resistance QTLs NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01,NLB_6.01, NLB_7.01, and NLB_9.01.

In another aspect, a corn plant, seed, or cell provided herein comprisesNLB resistance QTL NLB_3.01 and one or more NLB resistance QTLs selectedfrom the group consisting of NLB resistance QTLs NLB_2.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect,a corn plant, seed, or cell provided herein comprises NLB resistance QTLNLB_3.01 and two or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_4.01, NLB_4.02,NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_3.01 and three or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_4.01, NLB_4.02,NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_3.01 and four or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_4.01, NLB_4.02,NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_3.01 and five or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_4.01, NLB_4.02,NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_3.01 and or six or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_4.01, NLB_4.02,NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_3.01 and NLB resistance QTLs NLB_2.01, NLB_4.01, NLB_4.02, NLB_5.01,NLB_6.01, NLB_7.01, and NLB_9.01.

In another aspect, a corn plant, seed, or cell provided herein comprisesNLB resistance QTL NLB_4.01 and one or more NLB resistance QTLs selectedfrom the group consisting of NLB resistance QTLs NLB_2.01, NLB_3.01,NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect,a corn plant, seed, or cell provided herein comprises NLB resistance QTLNLB_4.01 and two or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.02,NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_4.01 and three or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.02,NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_4.01 and four or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.02,NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_4.01 and five or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.02,NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_4.01 and or six or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.02,NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_4.01 and NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.02, NLB_5.01,NLB_6.01, NLB_7.01, and NLB_9.01.

In another aspect, a corn plant, seed, or cell provided herein comprisesNLB resistance QTL NLB_4.02 and one or more NLB resistance QTLs selectedfrom the group consisting of NLB resistance QTLs NLB_2.01, NLB_3.01,NLB_4.01, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect,a corn plant, seed, or cell provided herein comprises NLB resistance QTLNLB_4.02 and two or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_4.02 and three or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_4.02 and four or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_4.02 and five or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_4.02 and or six or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_4.02 and NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_5.01,NLB_6.01, NLB_7.01, and NLB_9.01.

In another aspect, a corn plant, seed, or cell provided herein comprisesNLB resistance QTL NLB_5.01 and one or more NLB resistance QTLs selectedfrom the group consisting of NLB resistance QTLs NLB_2.01, NLB_3.01,NLB_4.01, NLB_4.02, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect,a corn plant, seed, or cell provided herein comprises NLB resistance QTLNLB_5.01 and two or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_5.01 and three or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_5.01 and four or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_5.01 and five or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_5.01 and or six or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_6.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_5.01 and NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02,NLB_6.01, NLB_7.01, and NLB_9.01.

In another aspect, a corn plant, seed, or cell provided herein comprisesNLB resistance QTL NLB_6.01 and one or more NLB resistance QTLs selectedfrom the group consisting of NLB resistance QTLs NLB_2.01, NLB_3.01,NLB_4.01, NLB_4.02, NLB_5.01, NLB_7.01, and NLB_9.01. In another aspect,a corn plant, seed, or cell provided herein comprises NLB resistance QTLNLB_6.01 and two or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_6.01 and three or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_6.01 and four or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_6.01 and five or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_6.01 and or six or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_7.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_6.01 and NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02,NLB_5.01, NLB_7.01, and NLB_9.01.

In another aspect, a corn plant, seed, or cell provided herein comprisesNLB resistance QTL NLB_7.01 and one or more NLB resistance QTLs selectedfrom the group consisting of NLB resistance QTLs NLB_2.01, NLB_3.01,NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01, and NLB_9.01. In another aspect,a corn plant, seed, or cell provided herein comprises NLB resistance QTLNLB_7.01 and two or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_6.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_7.01 and three or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_6.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_7.01 and four or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_6.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_7.01 and five or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_6.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_7.01 and or six or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_6.01, and NLB_9.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_7.01 and NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02,NLB_5.01, NLB_6.01, and NLB_9.01.

In another aspect, a corn plant, seed, or cell provided herein comprisesNLB resistance QTL NLB_9.01 and one or more NLB resistance QTLs selectedfrom the group consisting of NLB resistance QTLs NLB_2.01, NLB_3.01,NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01, and NLB_7.01. In another aspect,a corn plant, seed, or cell provided herein comprises NLB resistance QTLNLB_9.01 and two or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_6.01, and NLB_7.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_9.01 and three or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_6.01, and NLB_7.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_9.01 and four or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_6.01, and NLB_7.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_9.01 and five or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_6.01, and NLB_7.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_9.01 and or six or more NLB resistance QTLs selected from the groupconsisting of NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_6.01, and NLB_7.01. In another aspect, a cornplant, seed, or cell provided herein comprises NLB resistance QTLNLB_9.01 and NLB resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02,NLB_5.01, NLB_6.01, and NLB_7.01.

As an example, a corn plant or seed comprising one or more NLBresistance QTLs provided herein exhibits smaller leaf lesions comparedto a corn plant or seed lacking the one or more NLB resistance QTLsunder a high NLB stress condition. In an aspect, a corn plant or seedcomprising one or more NLB resistance QTLs provided herein exhibitsfewer leaf lesions compared to a corn plant or seed lacking the one ormore NLB resistance QTLs under a high NLB stress condition. In anaspect, a corn plant or seed comprising one or more NLB resistance QTLsprovided herein exhibits less leaf area covered by leaf lesions comparedto a corn plant or seed lacking the one or more NLB resistance QTLsunder a high NLB stress condition. In an aspect, a corn plant or seedcomprising one or more NLB resistance QTLs provided herein exhibitsreduced stem rot compared to a corn plant or seed lacking the one ormore NLB resistance QTLs under a high NLB stress condition. In anaspect, a corn plant or seed comprising one or more NLB resistance QTLsprovided herein exhibits reduced root rot compared to a corn plant orseed lacking the one or more NLB resistance QTLs under a high NLB stresscondition. In an aspect, a corn plant or seed comprising one or more NLBresistance QTLs provided herein exhibits less foliage destructioncompared to a corn plant or seed lacking the one or more NLB resistanceQTLs under a high NLB stress condition.

In an aspect, this disclosure provides a method comprising providing aset of corn seeds described in any one of paragraphs [00175] to [00183]to a person desirous of planting the set of corn seeds in a field plot.In an aspect, a method comprising a field plot that exhibits NLBinfection in any one of the previous one or more, two or more, three ormore, four or more, five or more, six or more, seven or more, eight ormore, nine or more, or ten or more planting seasons.

In an aspect, a method, a corn plant, or a corn seed provided herein isused in combination with one or more pesticides including, but notlimited to, herbicides, fungicides (e.g., picoxystrobin, cyproconazole,tetraconazole, pyraclostrobin, metconazole, azoxystrobin, propiconazole,prothioconazole, trifloxystrobin), insecticides, microbiocides,nematicides, insect repellents, bactericides, and other substances usedto control pests. In another aspect, a method, a corn plant, or a cornseed provided herein is used in combination with one or more triazoles,strobilurins, acylamino acids, pyrimidines, pyridines, arylphenylketones, amides, benzanilides, imidazoles, dinitrophenols, morpholines,phenylsulfamides and organophosphorus cpds, derivatives thereof andcombinations thereof which can be applied as a seed treatment, a foliartreatment, a drench treatment, or a drip treatment.

In an aspect, corn seeds provided herein are untreated. In anotheraspect, corn seeds provided herein can be subjected to various andmultiple treatments. For example, without being limiting, the seeds canbe treated to improve germination by priming the seeds, by disinfectionto protect against seed borne pathogens, or both priming anddisinfection. In another example, seeds can be coated with any availablecoating to improve, for example, plantability, seed emergence, andprotection against seed borne pathogens. Seed coating can be any form ofseed coating including, but not limited to, pelleting, film coating, andencrustments.

In a further example, the disclosure provides methods to enhance NLBresistance by combining two or more, three or more, five or more, six ormore, or seven or more NLB resistance QTLs provided herein. In anaspect, the combined NLB resistance QTLs have additive effects inproviding NLB resistance. In another aspect, the combined NLB resistanceQTLs have synergistic effects in providing NLB resistance. In a furtheraspect, the combination of two or more, three or more, four or more,five or more, six or more, or seven or more NLB resistance QTLs providedherein has no negative effects over corn physiology, resistance, yield,or performance in general.

In an aspect, this disclosure provides corn plant cells, tissues, andorgans that are not reproductive material and do not mediate the naturalreproduction of the plant. In one aspect, this disclosure provides anon-reproductive corn cell. In another aspect, this disclosure alsoprovides corn plant cells, tissues, and organs that are reproductivematerial and mediate the natural reproduction of the plant. In anotheraspect, this disclosure provides corn plant cells, tissues, and organsthat cannot maintain themselves via photosynthesis. In another aspect,this disclosure provides somatic corn plant cells. Somatic cells,contrary to germline cells, do not mediate plant reproduction.

As an example, the provided cells, tissues and organs can be from seed,fruit, leaf, leaf blade, leaf sheath, auricle, ligule, cotyledon,hypocotyl, meristem, embryos, endosperm, root, shoot, stem, pod, flower,inflorescence, stalk, pedicel, style, stigma, receptacle, petal, sepal,pollen, anther, filament, ovary, ovule, pericarp, phloem, bud, orvascular tissue. In another example, this disclosure provides a cornplant chloroplast or mitochondria. In a further example, this disclosureprovides epidermal cells, stomata cell, trichomes, root hairs, a storageroot, or a tuber. In another example, this disclosure provides a cornprotoplast.

Skilled artisans understand that corn plants naturally reproduce viaseeds, not via asexual reproduction or vegetative propagation. In anexample, this disclosure provides corn endosperm. In another example,this disclosure provides corn endosperm cells. In a further example,this disclosure provides a male or female sterile corn plant, whichcannot reproduce without human intervention.

In a further aspect, this disclosure provides processed products madefrom a provided corn plant, seed, or cell. As an example, such productsinclude, but are not limited to, meal, oil, plant extract, starch,fermentation products, or digestion products. In another example, thisdisclosure also provides a corn meal, which is substantially oil freeand which is produced using the oilseed of any of the plants providedherein. In another example, this disclosure also provides a method ofproviding a corn meal by crushing oilseed of any of the plants providedherein.

A corn plant, seed, or cell provided herein can also be geneticallyengineered to express various phenotypes of agronomic interest.Exemplary genes implicated in this regard include, but are not limitedto, genes that confer resistance to pests or disease, genes that conferresistance or tolerance to an herbicide, genes that control malesterility, genes that affect abiotic stress resistance, and other genesand transcription factors that affect plant growth and agronomic traitssuch as yield, flowering, plant growth, or plant architecture.

Corn Transformation

A corn plant, seed, or cell provided herein can be geneticallytransformed. Numerous methods for plant transformation have beendeveloped including biological and physical plant transformationprotocols. See, for example, Mild et al., “Procedures for IntroducingForeign DNA into Plants” in Methods in Plant Molecular Biology andBiotechnology, Glick B. R. and Thompson, J. E. Eds. (CRC Press, Inc.,Boca Raton, 1993) pages 67-88. In addition, expression vectors and invitro culture methods for plant cell or tissue transformation andregeneration of plants are available. See, for example, Gruber et al.,“Vectors for Plant Transformation” in Methods in Plant Molecular Biologyand Biotechnology, Glick B. R. and Thompson, J. E. Eds. (CRC Press,Inc., Boca Raton, 1993) pages 89-119.

One method for introducing an expression vector into plants is based onthe natural transformation system of Agrobacterium. See, e.g., Horsch etal., A Simple and General Method for Transferring Genes into Plants.Science, 227:1229-1231 (1985). A. tumefaciens and A. rhizogenes areplant pathogenic soil bacteria which genetically transform plant cells.Descriptions of Agrobacterium vector systems and methods forAgrobacterium-mediated gene transfer are provided by, for example, U.S.Pat. No. 5,563,055, incorporated herein by reference in its entirety.

Several methods of plant transformation, collectively referred to asdirect gene transfer, have been developed as an alternative toAgrobacterium-mediated transformation. A generally applicable method ofplant transformation is microprojectile-mediated transformation whereinDNA is carried on the surface of microprojectiles. The expression vectoris introduced into plant tissues with a biolistic device thataccelerates the microprojectiles to speeds of 300 to 600 m/s which issufficient to penetrate plant cell walls and membranes.

Another method for physical delivery of DNA to plants is sonication oftarget cells. Alternatively, liposome and spheroplast fusion have beenused to introduce expression vectors into plants. Electroporation ofprotoplasts and whole cells and tissues can also be used.

Following transformation of corn target tissues, expression of theabove-described selectable marker genes allows for preferentialselection of transformed cells, tissues, and/or plants, usingregeneration and selection methods well-known in the art.

The foregoing methods for transformation would typically be used forproducing a transgenic variety. The transgenic variety could then becrossed with another (non-transformed or transformed) variety, in orderto produce a new transgenic variety. Alternatively, a genetic traitwhich has been engineered into a particular corn line using theforegoing transformation techniques could be moved into another lineusing traditional backcrossing techniques that are well-known in theplant breeding arts. For example, a backcrossing approach could be usedto move an engineered trait from a public, non-elite variety into anelite variety, or from a variety containing a foreign gene in its genomeinto a variety or varieties which do not contain that gene.

A corn plant, seed, or cell provided herein can also be produced by oneor more genome engineering techniques or subject to further genomicediting. For example, one or more NLB resistance alleles can beintroduced into an NLB susceptible background. Exemplary genomeengineering techniques include meganucleases, zinc-finger nucleases,TALENs, and CRISPR/Cas9 systems. See, e.g., Gaj et al., ZFN, TALEN, andCRISPR/Cas-based methods for genome engineering. Trends inBiotechnology, 31:397-405 (2013). Additional genome engineeringtechniques known to those of ordinary skill in the art are alsoenvisioned.

Additional Breeding

A corn plant or seed provided herein can also be subject to additionalbreeding using one or more known methods in the art, e.g., pedigreebreeding, recurrent selection, mass selection, and mutation breeding.Pedigree breeding starts with the crossing of two genotypes, such as acorn variety comprising an NLB resistance QTL or NLB resistance alleleprovided herein and another corn variety lacking such a locus. If thetwo original parents do not provide all the desired characteristics,other sources can be included in the breeding population. In thepedigree method, superior plants are selfed and selected in successivefilial generations. In the succeeding filial generations theheterozygous condition gives way to homogeneous varieties as a result ofself-fertilization and selection. Typically in the pedigree method ofbreeding, five or more successive filial generations of selfing andselection is practiced: F₁ to F₂; F₂ to F₃; F₃ to F₄; F₄ to F₅, etc.After a sufficient amount of inbreeding, successive filial generationswill serve to increase seed of the developed variety. The developedvariety can comprise homozygous alleles at about 95% or more of itsloci.

In addition to being used to create a backcross conversion, backcrossingcan also be used in combination with pedigree breeding. As discussedpreviously, backcrossing can be used to transfer one or morespecifically desirable traits from one variety, the donor parent, to adeveloped variety called the recurrent parent, which has overall goodagronomic characteristics yet lacks that desirable trait or traits.However, the same procedure can be used to move the progeny toward thegenotype of the recurrent parent but at the same time retain manycomponents of the non-recurrent parent by stopping the backcrossing atan early stage and proceeding with selfing and selection. For example, acorn variety can be crossed with another variety to produce a firstgeneration progeny plant. The first generation progeny plant can then bebackcrossed to one of its parent varieties to create a BC1 or BC2.Progenies are selfed and selected so that the newly developed varietyhas many of the attributes of the recurrent parent and yet several ofthe desired attributes of the non-recurrent parent. This approachleverages the value and strengths of the recurrent parent for use in newcorn varieties.

Recurrent selection is a method used in a plant breeding program toimprove a population of plants. The method entails individual plantscross pollinating with each other to form progeny. The progeny are grownand the superior progeny selected by any number of selection methods,which include individual plant, half-sib progeny, full-sib progeny andselfed progeny. The selected progeny are cross pollinated with eachother to form progeny for another population. This population is plantedand again superior plants are selected to cross pollinate with eachother. Recurrent selection is a cyclical process and therefore can berepeated as many times as desired. The objective of recurrent selectionis to improve the traits of a population. The improved population canthen be used as a source of breeding material to obtain new varietiesfor commercial or breeding use, including the production of a syntheticline. A synthetic line is the resultant progeny formed by theintercrossing of several selected varieties.

Mass selection is another useful technique when used in conjunction withmolecular marker enhanced selection. In mass selection, seeds fromindividuals are selected based on phenotype or genotype. These selectedseeds are then bulked and used to grow the next generation. Bulkselection requires growing a population of plants in a bulk plot,allowing the plants to self-pollinate, harvesting the seed in bulk andthen using a sample of the seed harvested in bulk to plant the nextgeneration. Also, instead of self-pollination, directed pollinationcould be used as part of the breeding program.

Mutation breeding can also be used to introduce new traits into a cornplant or seed provided herein. Mutations that occur spontaneously or areartificially induced can be useful sources of variability for a plantbreeder. The goal of artificial mutagenesis is to increase the rate ofmutation for a desired characteristic. Mutation rates can be increasedby many different means including temperature, long-term seed storage,tissue culture conditions, radiation (such as X-rays, gamma rays (e.g.,cobalt-60 or cesium-137), neutrons (product of nuclear fission byuranium-235 in an atomic reactor), beta radiation (emitted fromradioisotopes such as phosphorus-32 or carbon-14), or ultravioletradiation (from 2500 to 2900 nm)), or chemical mutagens (such as baseanalogues (5-bromo-uracil), related compounds (8-ethoxy caffeine),antibiotics (streptonigrin), alkylating agents (sulfur mustards,nitrogen mustards, epoxides, ethylenamines, sulfates, sulfonates,sulfones, lactones), azide, hydroxylamine, nitrous acid, or acridines).Transposon- or T-DNA-based mutagenesis is also encompassed by thepresent disclosure. Once a desired trait is observed through mutagenesisthe trait can then be incorporated into existing germplasm bytraditional breeding techniques.

In an aspect, the disclosure provides a doubled haploid corn plant andseed that comprise an NLB resistance QTL or NLB resistance markeralleles provided herein. The doubled haploid approach achieves isogenicplants in a shorter time frame, and is particularly useful forgenerating inbred lines and quantitative genetics studies. Doubledhaploid plants can be produced according to methods known in the art.For example, the initial step involves the haploidization of the plantwhich results in the production of a population comprising haploid seed.Non-homozygous lines are crossed with an inducer parent, resulting inthe production of haploid seeds. Seeds that have haploid embryos, butnormal triploid endosperm, advance to the second stage. After selectinghaploid seeds from the population, the selected seeds undergo chromosomedoubling to produce doubled haploid seeds. A spontaneous chromosomedoubling in a cell lineage will lead to normal gamete production or theproduction of unreduced gametes from haploid cell lineages. Applicationof a chemical compound, such as colchicine, can be used to increase therate of diploidization. Colchicine binds to tubulin and prevents itspolymerization into microtubules, thus arresting mitosis at metaphase,can be used to increase the rate of diploidization, i.e. doubling of thechromosome number. These chimeric plants are self-pollinated to producediploid (doubled haploid) seed. This doubled haploid seed is cultivatedand subsequently evaluated and used in hybrid testcross production.

In an aspect, this disclosure also provides methods for making asubstantially homozygous corn plant by producing or obtaining a seedfrom a cross of a corn plant comprising an NLB resistance allele andanother corn plant and applying doubled haploid methods to the F₁ seedor F₁ plant or to any successive filial generation.

Hybrid Production

In an aspect, this disclosure provides a hybrid corn plant or seed, andtheir production. The development of a corn hybrid in a corn plantbreeding program generally involves three steps: (1) the selection ofplants from various germplasm pools for initial breeding crosses; (2)the selfing of the selected plants from the breeding crosses for severalgenerations to produce a series of inbred lines, which, althoughdifferent from each other, breed true and are highly uniform; and (3)crossing the selected inbred lines with different inbred lines toproduce the hybrids. During the inbreeding process in corn, the vigor ofthe lines decreases. Vigor is restored when two different inbred linesare crossed to produce the hybrid. An important consequence of thehomozygosity and homogeneity of the inbred lines is that the hybridbetween a defined pair of inbreds will always be the same. Once theinbreds that give a superior hybrid have been identified, the hybridseed can be reproduced indefinitely as long as the homogeneity of theinbred parents is maintained.

Combining ability of a line, as well as the performance of the line, isa factor in the selection of improved corn lines that can be used asinbreds. Combining ability refers to a line's contribution as a parentwhen crossed with other lines to form hybrids. The hybrids formed forthe purpose of selecting superior lines are designated test crosses. Oneway of measuring combining ability is by using breeding values. Breedingvalues are based on the overall mean of a number of test crosses. Thismean is then adjusted to remove environmental effects and it is adjustedfor known genetic relationships among the lines.

Hybrid seed production requires inactivation of pollen produced by thefemale parent. A pollination control system and effective transfer ofpollen from one parent to the other offers improved plant breeding andan effective method for producing hybrid corn seed and plants. Forexample, a male sterility system can be used to produce corn hybrids.

Male sterility genes can increase the efficiency with which hybrids aremade, in that they eliminate the need to physically emasculate the plantused as a female in a given cross. Where one desires to employmale-sterility systems, it can be beneficial to also utilize one or moremale-fertility restorer genes. For example, where cytoplasmic malesterility (CMS) is used, hybrid crossing requires three inbred lines:(1) a cytoplasmically male-sterile line having a CMS cytoplasm; (2) afertile inbred with normal cytoplasm, which is isogenic with the CMSline for nuclear genes (“maintainer line”); and (3) a distinct, fertileinbred with normal cytoplasm, carrying a fertility restoring gene(“restorer” line). The CMS line is propagated by pollination with themaintainer line, with all of the progeny being male sterile, as the CMScytoplasm is derived from the female parent. These male sterile plantscan then be efficiently employed as the female parent in hybrid crosseswith the restorer line, without the need for physical emasculation ofthe male reproductive parts of the female parent.

Marker Detection

In an aspect, the present disclosure provides markers that are inlinkage disequilibrium with at least one NLB resistance QTL or NLBresistance allele and can be used to select for NLB resistance.Exemplary markers comprise SEQ ID NOs: 1-89 and 446-482 with their NLBresistance alleles shown in Table 4. Markers within approximately 20 cM,15 cM, 10 cM, 5 cM, 4 cM, 3 cM, 2 cM, 1 cM, 0.5 cM or less than 0.5 cMof these exemplary markers can also be identified from the known art.

Genetic markers are distinguishable from each other (as well as from theplurality of alleles of any one particular marker) on the basis ofpolynucleotide length and/or sequence. In general, any differentiallyinherited polymorphic trait (including a nucleic acid polymorphism) thatsegregates among progeny is a potential genetic marker.

As a set, polymorphic markers serve as a useful tool for fingerprintingplants to inform the degree of identity of lines or varieties. Thesemarkers can form a basis for determining associations with phenotype andcan be used to drive genetic gain. The implementation of marker-assistedselection is dependent on the ability to detect and analyze underlyinggenetic differences between individuals.

As an example, nucleic acid analysis methods include, but are notlimited to, PCR-based detection methods, microarray methods, massspectrometry-based methods, and/or nucleic acid sequencing methods. Inan aspect, the detection of polymorphic sites in a sample of DNA, RNA,or cDNA can be facilitated through the use of nucleic acid amplificationmethods. Such methods specifically increase the concentration ofpolynucleotides that span the polymorphic site, or include that site andsequences located either distal or proximal to it. Such amplifiedmolecules can be readily detected by gel electrophoresis, fluorescencedetection methods, or other means.

A method of achieving such amplification employs the polymerase chainreaction (PCR) using primer pairs that are capable of hybridizing to theproximal sequences that define a polymorphism in its double-strandedform. Methods for typing DNA based on mass spectrometry have beenprovided in U.S. Pat. Nos. 6,613,509 and 6,503,710, and references foundtherein.

Polymorphisms in DNA sequences can be detected or typed by a variety ofeffective methods well known in the art including, but not limited to,those provided in U.S. Pat. Nos. 5,468,613, 5,217,863; 5,210,015;5,876,930; 6,030,787; 6,004,744; 6,013,431; 5,595,890; 5,762,876;5,945,283; 5,468,613; 6,090,558; 5,800,944; 5,616,464; 7,312,039;7,238,476; 7,297,485; 7,282,355; 7,270,981; and 7,250,252 all of whichare incorporated herein by reference in their entireties. However, thecompositions and methods of the present disclosure can be used inconjunction with any polymorphism typing method to type polymorphisms ingenomic DNA samples. These genomic DNA samples used include but are notlimited to genomic DNA isolated directly from a plant, cloned genomicDNA, or amplified genomic DNA.

For instance, polymorphisms in DNA sequences can be detected byhybridization to allele-specific oligonucleotide (ASO) probes asprovided in U.S. Pat. Nos. 5,468,613 and 5,217,863. U.S. Pat. No.5,468,613 discloses allele specific oligonucleotide hybridizations wheresingle or multiple nucleotide variations in nucleic acid sequence can bedetected in nucleic acids by a process in which the sequence containingthe nucleotide variation is amplified, spotted on a membrane and treatedwith a labeled sequence-specific oligonucleotide probe.

Target nucleic acid sequence can also be detected by probe ligationmethods as provided in U.S. Pat. No. 5,800,944 where sequence ofinterest is amplified and hybridized to probes followed by ligation todetect a labeled part of the probe.

Microarrays can also be used for polymorphism detection, whereinoligonucleotide probe sets are assembled in an overlapping fashion torepresent a single sequence such that a difference in the targetsequence at one point would result in partial probe hybridization(Borevitz et al., Large-scale identification of single-featurepolymorphisms in complex genomes. Genome Research, 13:513-523 (2003);Cui et al., Detecting single-feature polymorphisms using oligonucleotidearray and robustified projection pursuit. Bioinformatics, 21:3852-3858(2005)). On any one microarray, it is expected there will be a pluralityof target sequences, which can represent genes and/or noncoding regionswherein each target sequence is represented by a series of overlappingoligonucleotides, rather than by a single probe. This platform providesfor high throughput screening a plurality of polymorphisms. Asingle-feature polymorphism (SFP) is a polymorphism detected by a singleprobe in an oligonucleotide array, wherein a feature is a probe in thearray. Typing of target sequences by microarray-based methods isprovided in U.S. Pat. Nos. 6,799,122; 6,913,879; and 6,996,476.

Target nucleic acid sequence can also be detected by probe linkingmethods as provided in U.S. Pat. No. 5,616,464, employing at least onepair of probes having sequences homologous to adjacent portions of thetarget nucleic acid sequence and having side chains which non-covalentlybind to form a stem upon base pairing of the probes to the targetnucleic acid sequence. At least one of the side chains has aphotoactivatable group which can form a covalent cross-link with theother side chain member of the stem.

Other exemplary methods for detecting SNPs and Indels include singlebase extension (SBE) methods. Examples of SBE methods include, but arenot limited, to those provided in U.S. Pat. Nos. 6,004,744; 6,013,431;5,595,890; 5,762,876; and 5,945,283. SBE methods are based on extensionof a nucleotide primer that is adjacent to a polymorphism to incorporatea detectable nucleotide residue upon extension of the primer. In anaspect, the SBE method uses four synthetic oligonucleotides. Two of theoligonucleotides serve as PCR primers and are complementary to sequenceof the locus of genomic DNA which flanks a region containing thepolymorphism to be assayed. Following amplification of the region of thegenome containing the polymorphism, the PCR product is mixed with thethird and fourth oligonucleotides (called extension primers) which aredesigned to hybridize to the amplified DNA adjacent to the polymorphismin the presence of DNA polymerase and two differentially labeleddideoxynucleosidetriphosphates. If the polymorphism is present on thetemplate, one of the labeled dideoxynucleosidetriphosphates can be addedto the primer in a single base chain extension. The allele present isthen inferred by determining which of the two differential labels wasadded to the extension primer. Homozygous samples will result in onlyone of the two labeled bases being incorporated and thus only one of thetwo labels will be detected. Heterozygous samples have both allelespresent, and will thus direct incorporation of both labels (intodifferent molecules of the extension primer) and thus both labels willbe detected.

In another exemplary method for detecting polymorphisms, SNPs and indelscan be detected by methods provided in U.S. Pat. Nos. 5,210,015;5,876,930; and 6,030,787 in which an oligonucleotide probe having a 5′fluorescent reporter dye and a 3′ quencher dye covalently linked to the5′ and 3′ ends of the probe. When the probe is intact, the proximity ofthe reporter dye to the quencher dye results in the suppression of thereporter dye fluorescence, e.g., by Forster-type energy transfer. DuringPCR, forward and reverse primers hybridize to a specific sequence of thetarget DNA flanking a polymorphism while the hybridization probehybridizes to polymorphism-containing sequence within the amplified PCRproduct. In the subsequent PCR cycle DNA polymerase with 5′-3′exonuclease activity cleaves the probe and separates the reporter dyefrom the quencher dye resulting in increased fluorescence of thereporter.

As an example, the locus or loci of interest can be directly sequencedusing nucleic acid sequencing technologies. Methods for nucleic acidsequencing are known in the art and include technologies provided by 454Life Sciences (Branford, Conn.), Agencourt Bioscience (Beverly, Mass.),Applied Biosystems (Foster City, Calif.), LI-COR Biosciences (Lincoln,Nebr.), NimbleGen Systems (Madison, Wis.), Illumina (San Diego, Calif.),Pac-Bio (Menlo Park, Calif.) and VisiGen Biotechnologies (Houston,Tex.). Such nucleic acid sequencing technologies comprise formats suchas parallel bead arrays, sequencing by ligation, capillaryelectrophoresis, electronic microchips, “biochips,” microarrays,parallel microchips, and single-molecule arrays, as reviewed by Service,Gene sequencing: the race for the $1000 genome. Science, 311:1544-46(2006).

As an example, in silico methods can be used to detect the marker lociof interest. For example, the sequence of a nucleic acid comprising themarker locus of interest can be stored in a computer. The desired markerlocus sequence or its homolog can be identified using an appropriatenucleic acid search algorithm as provided by, for example, in suchreadily available programs as BLAST, or even simple word processors.

In an aspect, any of the aforementioned marker types can be employed inthe context of this disclosure to identify chromosome intervalsencompassing a genetic element that contributes to superior agronomicperformance (e.g., corn NLB resistance).

The markers to be used in the methods of the present disclosure shouldpreferably be diagnostic of origin in order for inferences to be madeabout subsequent populations. Experience to date suggests that SNPmarkers can be ideal for mapping because the likelihood that aparticular SNP allele is derived from independent origins in the extantpopulations of a particular species is very low. As such, SNP markersappear to be useful for tracking and assisting introgression of QTL,particularly in the case of genotypes.

Association Mapping

In an aspect, the present disclosure also provides chromosome intervals,marker loci, germplasm for conducting genome-wide association mappingfor NLB resistance. Exemplary chromosome intervals and marker loci areprovided in Tables 4 and 6. Genome-wide association mapping is conductedto find signals of association for various complex traits by surveyinggenetic variation in the whole genome.

Association mapping relies on chromosomal recombination opportunitiesover a large number of generations, in the history of a species, whichallows the removal of association between a QTL and any marker nottightly linked to it, thus improving the rate of discovery of trueassociation (Jannink and Walsh, Quantitative Genetics, Genomics andPlant Breeding, Kang, Ed. CAB International, pp. 59-68 (2002)).

An approach used to link phenotypic variation with genetic loci ismarker-trait association (MTA) mapping, also known as linkagedisequilibrium (LD) mapping. LD mapping emerged as an important genemapping tool in the early 1990's with the advent of high-throughputgenotyping technology, and has been widely used in human genetics toidentify genes affecting human diseases. This approach was introducedand began to be adopted in plant gene mapping studies in early 2000's(Flint-Garcia et al., Structure of linkage disequilibrium in plants.Annual Review of Plant Biology, 54:357-374 (2003)).

LD mapping assumes that the main cause for LD is linkage that binds locion the same chromosome together in transmission to next generation.However, due to recombination events accumulated over many generationsin a natural population, each chromosome has been shuffled deeply, sothat the chromosome has been broken into many tiny regions where lociremain transmitted together, but loci from different regions tend totransmit independently as if they were from different chromosomes.Chromosomal regions where loci are bound together in transmission arecommonly known as LD blocks (Reich et al., Linkage disequilibrium in thehuman genome. Nature, 411:199-204 (2001)). LD mapping identifies genesof interest through genetic markers on the LD blocks where the genes arelocated. This is done by detecting significant associations between themarkers and the traits that the genes affect with a sample of unrelatedindividuals or a sample of unrelated pedigrees that are genotyped on aselected set of markers covering candidate gene regions or the wholegenome, and phenotyped on a set of traits of interest.

Compared with traditional linkage mapping methods that are typicallybased on artificial biparental segregating populations (e.g., F₂, BC,doubled haploid, recombinant inbred line, etc.), LD mapping generallyproduces better mapping resolution, because of the smaller sizes of LDblocks. In addition, LD mapping is useful in identifying more than twofunctional alleles at associated markers in a germplasm. Further, LDmapping is efficient for evaluating natural populations.

Identification of QTLs

As an example, markers, alleles, and haplotypes provided herein can beused for identifying QTLs associated with NLB resistance. Thestatistical principles of QTL identification include penalizedregression analysis, ridge regression, single marker analysis, complexpedigree analysis, Bayesian MCMC, identity-by-descent analysis, intervalmapping, composite interval mapping (CIM), joint linkage mapping, andHaseman-Elston regression.

A QTL can act through a single gene mechanism or by a polygenicmechanism. In an aspect, the present disclosure provides an NLBresistance QTL interval, where an NLB resistance QTL (or multiple NLBresistance QTLs) that segregates with an NLB resistance trait iscontained in the chromosomal interval. As used herein, when a QTL (ormultiple QTLs) segregates with the NLB resistance trait, it is referredto herein as an “NLB resistance locus” (or “NLB resistance loci”).

In an aspect of this disclosure, the boundaries of an NLB resistance QTLinterval are drawn to encompass markers that will be closely linked toor associated with one or more NLB resistance QTLs. In other words, anNLB resistance QTL interval is drawn such that any marker that lieswithin that interval (including the terminal markers that define theboundaries of the interval) is genetically linked to or associated withthe NLB resistance QTL. Each interval comprises at least one NLBresistance QTL, and furthermore, can indeed comprise more than one NLBresistance QTL. Close proximity of multiple QTLs in the same intervalcan obfuscate the correlation of a particular marker with a particularQTL, as one marker can demonstrate linkage to more than one QTL.Conversely, e.g., if two markers in close proximity show co-segregationwith the desired phenotypic trait, it is sometimes unclear if each ofthose markers identifying the same QTL or two different QTLs.Regardless, knowledge of how many QTLs are in a particular interval isnot necessary to make or practice the claimed subject matter.

As an example, the present disclosure also provides the mapping ofadditional SNP markers associated with or closely linked to one or moreNLB resistance QTLs provided herein. SNP markers are ideal for mappingbecause the likelihood that a particular SNP allele is derived fromindependent origins in the extant populations of a particular species isvery low. As such, SNP markers are useful for tracking and assistingintrogression of NLB resistance QTLs, particularly in the case ofhaplotypes. In an aspect, a SNP marker is selected for mapping an NLBresistance QTL based on the marker's genetic map position. In anotheraspect, a SNP marker is selected for mapping an NLB resistance QTL basedon the marker's physical map position.

The genetic linkage of additional marker molecules can be established bya gene mapping model such as, without limitation, the flanking markermodel reported by Lander and Botstein, (Lander and Botstein, MappingMendelian Factors Underlying Quantitative Traits Using RFLP LinkageMaps. Genetics, 121:185-199 (1989)), and the interval mapping, based onmaximum likelihood methods described by Lander and Botstein (supra), andimplemented in the software package MAPMAKER/QTL (Lincoln and Lander,Mapping Genes Controlling Quantitative Traits Using MAPMAKER/QTL,Whitehead Institute for Biomedical Research, Massachusetts, (1990).Additional software includes Qgene, Version 2.23 (1996), Department ofPlant Breeding and Biometry, 266 Emerson Hall, Cornell University,Ithaca, N.Y., the manual of which is herein incorporated by reference inits entirety).

A maximum likelihood estimate (MLE) for the presence of a marker iscalculated, together with an MLE assuming no QTL effect, to avoid falsepositives. A log₁₀ of an odds ratio (LOD) is then calculated as:LOD=log₁₀ (MLE for the presence of a QTL/MLE given no linked QTL). TheLOD score essentially indicates how much more likely the data are tohave arisen assuming the presence of a QTL versus in its absence. TheLOD threshold value for avoiding a false positive with a givenconfidence, say 95%, depends on the number of markers and the length ofthe genome. Graphs indicating LOD thresholds are set forth in Lander andBotstein, (Lander and Botstein, Mapping Mendelian Factors UnderlyingQuantitative Traits Using RFLP Linkage Maps. Genetics, 121:185-199(1989), and further described by Arús and Moreno-Gonzilez, PlantBreeding, Hayward, Bosemark, Romagosa (eds.) Chapman & Hall, London, pp.314-331 (1993).

Additional models can be used. Many modifications and alternativeapproaches to interval mapping have been reported, including the use ofnon-parametric methods (Kruglyak and Lander, A Nonparametric Approachfor Mapping Quantitative Trait Loci. Genetics, 139:1421-1428 (1995), theentirety of which is herein incorporated by reference). Multipleregression methods or models can be also be used, in which the trait isregressed on a large number of markers (Jansen, Biometrics in PlantBreed, van Oijen, Jansen (eds.) Proceedings of the Ninth Meeting of theEucarpia Section Biometrics in Plant Breeding, The Netherlands, pp.116-124 (1994); Weber and Wricke, Advances in Plant Breeding, Blackwell,Berlin, 16 (1994)). Procedures combining interval mapping withregression analysis, whereby the phenotype is regressed onto a singleputative QTL at a given marker interval, and at the same time onto anumber of markers that serve as ‘cofactors,’ have been reported byJansen and Stam, High Resolution of Quantitative Traits Into MultipleLoci via Interval Mapping. Genetics, 136:1447-1455 (1994) and Zeng,Precision Mapping of Quantitative Trait Loci. Genetics, 136:1457-1468(1994). Generally, the use of cofactors reduces the bias and samplingerror of the estimated QTL positions (Utz and Melchinger, Biometrics inPlant Breeding, van Oijen, Jansen (eds.) Proceedings of the NinthMeeting of the Eucarpia Section Biometrics in Plant Breeding, TheNetherlands, pp. 195-204 (1994)), thereby improving the precision andefficiency of QTL mapping (Zeng, Precision Mapping of Quantitative TraitLoci. Genetics, 136:1457-1468 (1994)). These models can be extended tomulti-environment experiments to analyze genotype-environmentinteractions (Jansen et al., Genotype-by-environment interaction ingenetic mapping of multiple quantitative trait loci. Theoretical andApplied Genetics, 91:33-37 (1995)).

In an aspect, this disclosure provides chromosomal intervals comprisingQTL associated with NLB resistance. In an aspect, the chromosomeintervals of this disclosure are characterized by genomic regionsincluding and flanked by any two of marker loci SEQ ID NOs: 12 to 15. Inanother aspect, the chromosome intervals of this disclosure arecharacterized by genomic regions including and flanked by any two ofmarker loci SEQ ID NOs: 22 to 25. In another aspect, the chromosomeintervals of this disclosure are characterized by genomic regionsincluding and flanked by any two of marker loci SEQ ID NOs: 37 to 42 and474. In another aspect, the chromosome intervals of this disclosure arecharacterized by genomic regions including and flanked by any two ofmarker loci SEQ ID NOs: 44 to 49. In another aspect, the chromosomeintervals of this disclosure are characterized by genomic regionsincluding and flanked by any two of marker loci SEQ ID NOs: 57 to 62 and458 to 466. In another aspect, the chromosome intervals of thisdisclosure are characterized by genomic regions including and flanked byany two of marker loci SEQ ID NOs: 79 to 81. In another aspect, thechromosome intervals of this disclosure are characterized by genomicregions including and flanked by any two of marker loci SEQ ID NOs: 87to 89, 477, and 480. In another aspect, the chromosome intervals of thisdisclosure are characterized by genomic regions including and flanked bythe marker loci SEQ ID NOs: 469 and 470.

In an aspect, this disclosure provides chromosomal intervals comprisingQTL associated with NLB resistance. In an aspect, the chromosomeintervals of this disclosure are characterized by genomic regionsincluding and flanked by any two of marker loci SEQ ID NOs: 8 to 18. Inanother aspect, the chromosome intervals of this disclosure arecharacterized by genomic regions including and flanked by any two ofmarker loci SEQ ID NOs: 21 to 29. In another aspect, the chromosomeintervals of this disclosure are characterized by genomic regionsincluding and flanked by any two of marker loci SEQ ID NOs: 33 to 42,473, and 474. In another aspect, the chromosome intervals of thisdisclosure are characterized by genomic regions including and flanked byany two of marker loci SEQ ID NOs: 43 to 49 and 475. In another aspect,the chromosome intervals of this disclosure are characterized by genomicregions including and flanked by any two of marker loci SEQ ID NOs: 57to 64 and 458 to 468. In another aspect, the chromosome intervals ofthis disclosure are characterized by genomic regions including andflanked by any two of marker loci SEQ ID NOs: 74 to 82. In anotheraspect, the chromosome intervals of this disclosure are characterized bygenomic regions including and flanked by any two of marker loci SEQ IDNOs: 86 to 89, 476, 477, 479, and 480.

This disclosure also provides multiple markers linked to or associatedwith an NLB resistance QTL, for example, the markers having the sequenceselected from SEQ ID NOs: 1-89 and 446-482. This disclosure thereforeprovides plants comprising a nucleic acid molecule selected from thegroup consisting of SEQ ID NOs: 1-89 and 446-482, fragments thereof, orcomplements thereof. The present disclosure further provides a plantcomprising alleles of the chromosome interval linked to or associatedwith NLB resistance or fragments and complements thereof as well as anyplant comprising any combination of two or more NLB resistance allelesof marker loci selected from the group consisting of SEQ ID NOs: 1-89and 446-482. Plants provided by this disclosure can be homozygous orheterozygous for such alleles.

The compositions and methods of the present disclosure can be utilizedto guide MAS or breeding corn varieties with a desired complement (set)of allelic forms of chromosome intervals associated with superioragronomic performance (e.g., NLB resistance). Any of the provided markeralleles can be introduced into a corn line via introgression, bytraditional breeding (or introduced via transformation, or both) toyield a corn plant with superior agronomic performance. The number ofalleles associated with NLB resistance that can be introduced or bepresent in a corn plant of the present disclosure ranges from 1 to thenumber of alleles provided herein, each integer of which is incorporatedherein as if explicitly recited.

MAS using additional markers flanking either side of the DNA locusprovide further efficiency because an unlikely double recombinationevent would be needed to simultaneously break linkage between the locusand both markers. Moreover, using markers tightly flanking a locus, oneskilled in the art of MAS can reduce linkage drag by more accuratelyselecting individuals that have less of the potentially deleteriousdonor parent DNA. Any marker linked to or among the chromosome intervalsdescribed herein can thus find use within the scope of this disclosure.

These marker loci can be introgressed into any desired genomicbackground, germplasm, plant, line, variety, etc., as part of an overallMAS breeding program designed to enhance NLB resistance. This disclosurealso provides QTL intervals that can be used in MAS to select plantsthat demonstrate NLB resistance. Similarly, QTL intervals can also beused to counter-select plants that are lacking NLB resistance. Byidentifying plants lacking a desired marker locus, plants lacking NLBresistance can be identified and selected or eliminated from subsequentcrosses.

The present disclosure also extends to a method of making a progeny cornplant and the resulting progeny corn plants. In an aspect, the methodcomprises crossing a first parent corn plant with a second corn plantand growing the corn plant parent under plant growth conditions to yieldcorn plant progeny. Methods of crossing and growing a corn plant arewell within the ability of those of ordinary skill in the art. Such cornplant progeny can be assayed for alleles associated with NLB resistanceas provided herein and, thereby, the desired progeny selected. Suchprogeny plants or seed thereof can be sold commercially for cornproduction, used for food, processed to obtain a desired constituent ofthe corn, or further utilized in subsequent rounds of breeding. At leastone of the first or second corn plants can be a corn plant of thepresent disclosure in that it comprises at least one of the allelicforms of the markers of the present disclosure, such that the progenyare capable of inheriting the allele.

By providing the positions in the corn genome of QTL intervals and theassociated markers within those intervals, this disclosure also allowsone skilled in the art to identify and use other markers within theintervals provided herein or linked to or associated with the intervalsprovided herein. Having identified such markers, these intervals can bereadily identified from public linkage maps.

Closely linked markers flanking the locus of interest that have allelesin linkage disequilibrium (LD) with an NLB resistance allele at thatlocus can be effectively used to select for progeny plants with NLBresistance. Thus, the markers described herein, such as those listed inTable 4, as well as other markers genetically linked to or associatedwith the same chromosome interval, can be used to select for a cornplant, seed, or cell with NLB resistance. Often, a set of these markerswill be used, (e.g., 2 or more, 3 or more, 4 or more, 5 or more) in theflanking regions of the locus. Optionally, as described above, a markerflanking or within the actual locus can also be used. The parents andtheir progeny can be screened for these sets of markers, and the markersthat are polymorphic between the two parents used for selection. In anintrogression program, this allows for selection of the gene or locusgenotype at the more proximal polymorphic markers and selection for therecurrent parent genotype at the more distal polymorphic markers.

The choice of markers actually used to practice this disclosure is notlimited and can be any marker that is genetically linked to orassociated with the QTL intervals as described in Table 6, includingmarkers within approximately 20 cM, 15 cM, 10 cM, 5 cM, 4 cM, 3 cM, 2cM, 1 cM, 0.5 cM or less than 0.5 cM of the intervals provided herein.Examples include, but are not limited to, any marker selected from SEQID NOs: 1-89 and 446-482. In an aspect, a marker locus selected from SEQID NOs: 1-89 and 446-482 can be amplified using an appropriate pair ofprimers as indicated in Table 5. Furthermore, since there are manydifferent types of marker detection assays known in the art, it is notintended that the type of marker detection assay used to practice thisdisclosure be limited in any way.

Marker Assisted Selection (MAS) Breeding

Marker loci and their NLB resistance alleles provided herein can be usedin MAS breeding of NLB resistance. The more tightly linked a marker iswith a DNA locus influencing a phenotype (e.g., NLB resistance), themore reliable the marker is in MAS, as the likelihood of a recombinationevent unlinking the marker and the locus decreases. Markers containingthe causal mutation for a trait, or that are within the coding sequenceof a causative gene, are ideal as no recombination is expected betweenthem and the sequence of DNA responsible for the phenotype. However,markers do not need to contain or correspond to causal mutations inorder to be effective in MAS. In fact, most MAS breeding only usesmarkers linked to or associated with a causal mutation.

Developing molecular markers in crop species can increase efficiency inplant breeding through MAS. Genetic markers are used to identify plantsthat contain a desired genotype at one or more loci, and that areexpected to transfer the desired genotype, along with a desiredphenotype to their progeny. Genetic markers can be used to identifyplants containing a desired genotype at one locus, or at severalunlinked or linked loci (e.g., a haplotype), and that would be expectedto transfer the desired genotype, along with a desired phenotype totheir progeny. The present disclosure provides the means to identifyplants that exhibit NLB resistance by identifying chromosomal intervalsand genetic markers associated with NLB resistance.

In general, MAS uses polymorphic markers that have been identified ashaving a significant likelihood of co-segregation with a desired trait.Such markers are presumed to map near a gene or genes that give theplant its desired phenotype, and are considered indicators for thedesired trait.

Identification of plants or germplasm that include a marker locus ormarker loci linked to a desired trait or traits provides a basis forperforming MAS. Plants that comprise favorable markers or favorablealleles are selected for, while plants that comprise markers or allelesthat are negatively correlated with the desired trait can be selectedagainst. Desired markers and/or alleles can be introgressed into plantshaving a desired (e.g., elite or exotic) genetic background to producean introgressed plant or germplasm having the desired trait. In anaspect, it is contemplated that a plurality of markers for desiredtraits are sequentially or simultaneous selected and/or introgressed.The combinations of markers that are selected for in a single plant isnot limited, and can include any combination of markers provided hereinor any marker linked to the markers provided herein, or any markerslocated within the QTL intervals defined herein.

In an aspect, a first corn plant or germplasm exhibiting a desired trait(the donor, e.g., an NLB resistant corn plant) can be crossed with asecond corn plant or germplasm (the recipient; e.g., an elite or exoticcorn, depending on characteristics that are desired in the progeny) tocreate an introgressed corn plant or germplasm as part of a breedingprogram. In an aspect, the recipient plant can also contain one or moreloci associated with one or more desired traits, which can bequalitative or quantitative trait loci. In another aspect, the recipientplant can contain a transgene.

In an aspect, the recipient corn plant or germplasm will typically lackdesired traits as compared to the first corn plant or germplasm, whilethe introgressed corn plant or germplasm will display improved traits ascompared to the second plant or germplasm. An introgressed corn plant orgermplasm produced by these methods are also a feature of thisdisclosure.

MAS is a powerful shortcut to select for desired phenotypes and forintrogressing desired traits into cultivars (e.g., introgressing desiredtraits into elite lines). MAS is easily adapted to high throughputmolecular analysis methods that can quickly screen large numbers ofplant or germplasm genetic material for the markers of interest and ismuch more cost effective than cultivating and observing plants forvisible traits.

Genomic Selection

Genomic selection (GS), also known as genome wide selection (GWS), is aform of MAS that estimates all locus, haplotype, and/or marker effectsacross the entire genome to calculate genomic estimated breeding values(GEBVs). See Nakaya and Isobe, Will genomic selection be a practicalmethod for plant breeding? Annals of Botany 110: 1303-1316 (2012); VanVleck et al., Estimated breeding values for meat characteristics ofcross-bred cattle with an animal model. Journal of Animal Science 70:363-371 (1992); and Heffner et al., Genomic selection for cropimprovement. Crop Science 49: 1-12 (2009). GS utilizes a training phaseand a breeding phase. In the training phase, genotypes and phenotypesare analyzed in a subset of a population to generate a GS predictionmodel that incorporates significant relationships between phenotypes andgenotypes. A GS training population must be representative of selectioncandidates in the breeding program to which GS will be applied. In thebreeding phase, genotype data are obtained in a breeding population,then favorable individuals are selected based on GEBVs obtained usingthe GS prediction model generated during the training phase without theneed for phenotypic data.

Larger training populations typically increase the accuracy of GEBVpredictions. Increasing the training population to breeding populationratio is helpful for obtaining accurate GEBVs when working withpopulations having high genetic diversity, small breeding populations,low heritability of traits, or large numbers of QTLs. The number ofmarkers required for GS modeling is determined based on the rate of LDdecay across the genome, which must be calculated for each specificpopulation to which GS will be applied. In general, more markers will benecessary with faster raters of LD decay. Ideally, GS comprises at leastone marker in LD with each QTL, but in practical terms one of ordinaryskill in the art would recognized that this is not necessary.

With genotyping data, favorable individuals from a population can beselected based only on GEBVs. GEBVs are the sum of the estimate ofgenetic deviation and the weighted sum of estimates of breed effects,which are predicted using phenotypic data. Without being limiting,commonly used statistical models for prediction of GEBVs include bestlinear unbiased prediction (Henderson, Best linear unbiased estimationand prediction under a selection model. Biometrics 31: 423 (1975)) and aBayesian framework (Gianola and Fernando, Bayesian methods in animalbreeding theory. Journal of Animal Science 63: 217-244 (1986)).

The compositions and methods of the present disclosure can be utilizedfor GS or breeding corn varieties with a desired complement (set) ofallelic forms of chromosome intervals associated with superior agronomicperformance (e.g., NLB resistance). In an aspect, a corn plant, seed, orcell provided herein can be selected using genomic selection. In anotheraspect, SEQ ID NOs: 1-89 and 446-482 can be used in a method comprisinggenomic selection. In another aspect, a genomic selection methodprovided herein comprises phenotyping a population of corn plants forNLB resistance using the NLB rating scale provided in Table 1. Inanother aspect, a genomic selection method provided herein comprisesgenotyping a population of corn plants, seeds, or cells with at leastone of marker loci SEQ ID NOs: 1-89 and 446-482.

Introgression of NLB Resistance QTLs Using MAS

The disclosure provides methods and markers for introgressing one ormore NLB resistance QTLs provided herein into a new corn variety usingMAS.

Multiple methods are available to achieve the introgression. Forexample, introgression of a desired allele at a specified locus can betransmitted to at least one progeny via a cross between two parents ofthe same species, where at least one of the parents has the desiredallele in its genome. Alternatively, for example, transmission of anallele can occur by recombination between two donor genomes, e.g., in afused protoplast, where at least one of the donor protoplasts has thedesired allele in its genome. The desired allele can be, e.g., aselected allele of a marker, a QTL, a transgene, or the like. In anycase, offspring comprising the desired allele can be repeatedlybackcrossed to a line having a desired genetic background and selectedfor the desired allele, to result in the allele becoming fixed in aselected genetic background.

The introgression of one or more desired loci from a donor line intoanother line is achieved via repeated backcrossing to a recurrent parentaccompanied by selection to retain one or more loci from the donorparent. Markers associated with NLB resistance are assayed in progenyand those progeny with one or more desired markers are selected foradvancement. In another aspect, one or more markers can be assayed inthe progeny to select for plants with the genotype of the agronomicallyelite parent.

It is generally anticipated that trait introgression activities willrequire more than one generation, wherein progeny are crossed to therecurrent (agronomically elite) parent or selfed. Selections are madebased on the presence of one or more markers linked to NLB resistanceand can also be made based on the recurrent parent genotype, whereinscreening is performed on a genetic marker and/or phenotype basis. Inanother aspect, markers of this disclosure can be used in conjunctionwith other markers, ideally at least one on each chromosome of the corngenome, to track the introgression of NLB resistance into elitegermplasm. In another aspect, QTL intervals associated with NLBresistance will be useful in conjunction with SNP molecular markers ofthe present disclosure to combine quantitative and qualitative NLBresistance in the same plant. It is within the scope of this disclosureto utilize the methods and compositions for trait integration of NLBresistance. It is contemplated by the inventors that the presentdisclosure will be useful for developing commercial varieties with NLBresistance and other agronomically elite phenotypes.

The following non-limiting embodiments are envisioned:

-   -   1. A method of creating a population of corn plants, seeds, or        cells, said method comprising:        -   a. genotyping a first population of corn plants, seeds, or            cells at one or more marker loci associated with and within            about 10 cM of one or more Northern Leaf Blight (NLB)            resistance quantitative trait loci (QTLs) selected from the            group consisting of NLB resistance QTLs NLB_2.01, NLB_3.01,            NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, and            NLB_9.01;        -   b. selecting from said first population one or more corn            plants, seeds, or cells comprising one or more NLB            resistance alleles of said one or more marker loci; and        -   c. producing from said selected one or more corn plants,            seeds, or cells a second population of corn plants, seeds,            or cells comprising said one or more NLB QTLs.    -   2. The method of embodiment 1, wherein said one or more marker        loci are located in a chromosomal interval flanked by:        -   any two of marker loci SEQ ID NOs: 1 to 18;        -   any two of marker loci SEQ ID NOs: 19 to 31;        -   any two of marker loci SEQ ID NOs: 32 to 52 and 471 to 475;        -   any two of marker loci SEQ ID NOs: 53 to 65 and 446 to 468;        -   any two of marker loci SEQ ID NOs: 66 to 84;        -   any two of marker loci SEQ ID NOs: 85 to 89 and 476 to 482;            or        -   marker loci SEQ ID NOs: 469 and 470.    -   3. The method of embodiments 1 or 2, wherein said one or more        marker loci are located in a chromosomal interval flanked by:        -   any two marker loci selected from the group consisting of            SEQ ID NOs: 12 to 15;        -   any two marker loci selected from the group consisting of            SEQ ID NOs: 22 to 25;        -   any two marker loci selected from the group consisting of            SEQ ID NOs: 37 to 42 and 474;        -   any two marker loci selected from the group consisting of            SEQ ID NOs: 44 to 49;        -   any two marker loci selected from the group consisting of            SEQ ID NOs: 57 to 62 and 458 to 466;        -   any two marker loci selected from the group consisting of            SEQ ID NOs: 79 to 81;        -   any two marker loci selected from the group consisting of            SEQ ID NOs: 87 to 89, 477, and 480; or        -   marker loci SEQ ID NOs: 469 and 470.    -   4. The method of embodiments 1 or 2, wherein said one or more        marker loci are located in a chromosomal interval flanked by:        -   any two marker loci selected from the group consisting of            SEQ ID NOs: 8 to 18;        -   any two marker loci selected from the group consisting of            SEQ ID NOs: 21 to 29;        -   any two marker loci selected from the group consisting of            SEQ ID NOs: 33 to 42, 473, and 474;        -   any two marker loci selected from the group consisting of            SEQ ID NOs: 43 to 49 and 475;        -   any two marker loci selected from the group consisting of            SEQ ID NOs: 57 to 64 and 458 to 468;        -   any two marker loci selected from the group consisting of            SEQ ID NOs: 74 to 82;        -   any two marker loci selected from the group consisting of            SEQ ID NOs: 86 to 89, 476, 477, 479, and 480; or        -   marker loci SEQ ID NOs: 469 and 470.    -   5. The method of any one of embodiments 1-4, wherein said one or        more marker loci are within about 5 cM, 1 cM, 0.5 cM, or less        than 0.5 cM of any one of marker loci selected from the group        consisting of SEQ ID NOs: 1-89 and 446-482.    -   6. The method of any one of embodiments 1-5, wherein said one or        more NLB resistance QTLs provide mild resistance or resistance        to infection by Exserohilum turcicum.    -   7. The method of any one of embodiments 1-6, wherein said second        population of corn plants or seeds exhibit reduced root rot,        reduced stalk rot, fewer leaf lesions, less foliage destruction,        or any combination thereof compared to corn plants or seeds        lacking said NLB resistance QTL under a high NLB stress        condition.    -   8. The method of any one of embodiments 1-7, wherein said one or        more NLB resistance QTLs confer no yield penalty under a low NLB        stress condition.    -   9. The method of any one of embodiments 1-8, wherein said        step (a) comprises assaying a single nucleotide polymorphism        marker.    -   10. The method of any one of embodiments 1-9, wherein said        step (a) comprises the use of an oligonucleotide probe.    -   11. The method of embodiment 10, wherein said oligonucleotide        probe is adjacent to a polymorphic nucleotide position in said        marker locus.    -   12. The method of any one of embodiments 1-11, wherein said        step (a) comprises detecting a haplotype.    -   13. A method of introgressing an NLB resistance QTL, said method        comprising:        -   a. crossing a first corn plant comprising an NLB resistance            QTL with a second corn plant of a different genotype to            produce one or more progeny plants or seeds; and        -   b. selecting a progeny plant or seed comprising an NLB            resistance allele of a polymorphic locus linked to said NLB            resistance QTL, wherein said polymorphic locus is in a            chromosomal segment flanked by:            -   any two of marker loci SEQ ID NOs: 1 to 18;            -   any two of marker loci SEQ ID NOs: 19 to 31;            -   any two of marker loci SEQ ID NOs: 32 to 52 and 471 to                475;            -   any two of marker loci SEQ ID NOs: 53 to 65 and 446 to                468;            -   any two of marker loci SEQ ID NOs: 66 to 84;            -   any two of marker loci SEQ ID NOs: 85 to 89 and 476 to                482; or            -   marker loci SEQ ID NOs: 469 and 470.    -   14. The method of embodiment 13, wherein said polymorphic locus        is within about 10 cM, 5 cM, 1 cM, 0.5 cM, or less than 0.5 cM        of any one of marker loci selected from the group consisting of        SEQ ID NOs: 1-89 and 446-482.    -   15. The method of embodiment 13 or 14, further comprising:        -   c. crossing said progeny plant with itself or said second            plant to produce one or more further progeny plants or            seeds; and        -   d. selecting a further progeny plant or seed comprising said            NLB resistance allele.    -   16. An NLB resistant corn plant, seed, or cell comprising a        combination of two or more, three or more, four or more, five or        more, six or more, or seven or more introgressed NLB resistance        QTLs selected from the group consisting of NLB resistance QTLs        NLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01,        NLB_7.01, and NLB_9.01.    -   17. The corn plant, seed, or cell of embodiment 16, wherein seed        yield of said corn plant is about 1% or more, 3% or more, 5% or        more, 10% or more, 20% or more, 30% or more, 40% or more, 50% or        more, 60% or more, 70% or more, 80% or more, 90% or more, or        100% or more higher than seed yield of a corn plant without said        combination of introgressed NLB resistance QTLs under a high NLB        stress condition.    -   18. The corn plant, seed, or cell of embodiment 16 or 17,        wherein said corn plant, seed, or cell is in an agronomically        elite background.    -   19. The corn plant, seed, or cell of any one of embodiments        16-18, wherein said corn plant or seed is a transgenic hybrid        plant, seed, or cell.    -   20. The corn plant, seed, or cell of any one of embodiments        16-19, wherein said combination of introgressed NLB resistance        QTLs comprises one or more QTLs selected from the group        consisting of NLB resistance QTLs NLB_4.01 and NLB_4.02.    -   21. The corn plant, seed, or cell of any one of embodiments        16-19, wherein said combination of introgressed NLB resistance        QTLs comprises NLB resistance QTL NLB_4.01 and at least one NLB        resistance QTL selected from the group consisting of NLB_2.01,        NLB_3.01, NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01.    -   22. The corn plant, seed, or cell of any one of embodiments        16-19, wherein said combination of introgressed NLB resistance        QTLs comprises NLB resistance QTL NLB_4.02 and at least one NLB        resistance QTL selected from the group consisting of NLB_2.01,        NLB_3.01, NLB_4.01, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01.    -   23. The corn plant, seed, or cell of any one of embodiments        16-19, wherein said combination of introgressed NLB resistance        QTLs comprises NLB resistance QTLs NLB_4.01 and NLB_4.02, and at        least one NLB resistance QTL selected from the group consisting        of NLB_2.01, NLB_3.01, NLB_5.01, NLB_6.01, NLB_7.01, and        NLB_9.01.    -   24. A method for selecting a corn plant, seed, or cell, said        method comprising:        -   a. isolating nucleic acids from a corn plant, seed, or cell;        -   b. analyzing said nucleic acids to detect a polymorphic            marker associated with and within 10 cM of an NLB resistance            QTL selected from the group consisting of NLB resistance            QTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01,            NLB_6.01, NLB_7.01, and NLB_9.01; and        -   c. selecting a corn plant, seed, or cell comprising said NLB            resistance QTL.    -   25. A method comprising providing a set of corn seeds comprising        one or more, two or more, three or more, four or more, five or        more, six or more, or seven or more NLB resistance QTLs selected        from the group consisting of NLB resistance QTLs NLB_2.01,        NLB_3.01, NLB_4.01, NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, and        NLB_9.01, to a person desirous of planting said set of corn        seeds in a field plot.    -   26. A method of growing a population of corn plants in a field        plot, said method comprising planting a population of corn seeds        comprising one or more, two or more, three or more, four or        more, five or more, six or more, or seven or more introgressed        NLB resistance QTLs selected from the group consisting of NLB        resistance QTLs NLB_2.01, NLB_3.01, NLB_4.01, NLB_4.02,        NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01 in said field plot.

Having now generally described the invention, the same will be morereadily understood through reference to the following examples that areprovided by way of illustration, and are not intended to be limiting ofthe present invention, unless specified.

Each periodical, patent, and other document or reference cited herein isherein incorporated by reference in its entirety.

EXAMPLES Example 1. Identification of QTLs Associated with Northern LeafBlight Resistance in Biparental Mapping Populations

Biparental mapping populations are constructed to investigate thegenetic basis of northern leaf blight (NLB) disease resistance in corn.Plant phenotyping is performed in field plots. About 30-40 plots permapping population, each plot comprising 10 to 12 individual plants, areinoculated with E. turcicum by placing a sorghum seed carrying E.turcicum spores in the whorl of each plant between V6 (six leaf collarsvisible) stage and V8 stage. NLB disease resistance is measured 14-21days after inoculation by rating the percentage of leaf area infected ona scale of 1 (highly resistant) to 9 (susceptible) as shown in Table 1.

TABLE 1 Description of NLB rating scale, ILA = infected leaf area.Symptoms Score Rating 0% of leaf area infected; no visible lesions 1Highly Resistant ILA < 1%; few lesions, dispersed through 2 HighlyResistant lower leaves 1% ≤ ILA < 20% 3 Resistant 20% ≤ ILA < 40% 4Resistant 40% ≤ ILA < 50%; lesions reaching ear leaf, 5 Mildly Resistantwith sparse lesions in the leaves above the ear 50% ≤ ILA < 60%; lesionsreaching the leaves 6 Mildly above the ear Susceptible 60% ≤ ILA < 75% 7Susceptible 75% ≤ ILA < 90% 8 Susceptible >90% of foliar area infected,with premature 9 Susceptible death of the plant before forming blacklayer

Sixteen mapping populations are shown in Table 2. These populationsinclude twelve NLB resistant parents (CV114258, CV115214, CV099829,CV102084, CV095508, CV103141, CV105893, CV595358, CV593417, CV117407,CV592505, and CV592420). Each mapping population is scored for NLBresistance and individual plant scores from rows of 20 plants each areaveraged and reported as a final score for the row.

Plants from all mapping populations are genotyped using SNP markers thatcollectively span each chromosome in the maize genome. Marker-traitassociation studies are performed to identify NLB disease resistanceQTLs and their associated markers using composite interval mapping(CIN4) and single marker analysis (SMA).

TABLE 2 Mapping populations. Map- NLB ping NLB Suscep- Popula- Resistanttible Population tion Cross Line Line Type A CV113018/CV114258 CV114258CV113018 Double-haploid B CV115214/CV236864 CV115214 CV236864 F₄ CCV108503/CV099829 CV099829 CV108503 Double-haploid D CV102084/CV108986CV102084 CV108986 Double-haploid E CV102084/CV109562 CV102084 CV109562Double-haploid F CV102084/CV112706 CV102084 CV112706 Double-haploid GCV095508/CV095869 CV095508 CV095869 Double-haploid H CV095508/CV097202CV095508 CV097202 F₃ I CV112894/CV103141 CV103141 CV112894 F₃ JCV105893/CV112894 CV105893 CV112894 F₃ K CV595358/CV589205 CV595358CV589205 Double-haploid L CV582063/CV593417 CV593417 CV582063Double-haploid M CV625558/CV593417 CV593417 CV625558 Double-haploid OCV603347/CV117407 CV117407 CV603347 Double-haploid P CV592505/CV031573CV592505 CV031573 Double-haploid Q CV112894/CV592420 CV592420 CV112894F₃

Example 2. Identification of NLB Disease Resistance QTLs Via CompositeInterval Mapping

A composite interval mapping (CIM) approach is taken to identify NLBresistance QTL intervals based on the phenotyping and genotyping datacollected in Example 1. For each marker, the thresholds of likelihoodratio between full and null models for CIM are based on 1000 randompermutation tests (Churchill and Doerg, Genetics, 138(3):963-71 (1994)).The composite interval mapping (CIM) analysis reveals several strongQTLs associated with NLB resistance. The QTLs are confirmed in multiplegenetic backgrounds and summarized in Table 3.

In Table 3, genetic positions are represented in cM with position zerobeing the first (most distal) marker known at the beginning of thechromosome on Monsanto's internal consensus genetic map. Each row ofTable 3 provides mapping population ID, number of SNP markers genotyped,resistant parent, chromosome position, the peak of the likelihood ratiocorresponding to NLB resistance, left and right flanking positions,p-value, additive effect, and the phenotypic variance (R²) of individualQTL or Total QTLs.

TABLE 3 CIM results from all mapping populations. Number of QTLPositions (cM) Mapping Markers Resistant Left Right p- Individual Totalpopulation Genotyped Parent Chr Peak Flank Flank value* Additive QTL R²R² A 112 CV114258 4 168.3 152.3 175.5 0.01 0.53 0.21 0.58 B 90 CV1152144 155 152 158 0.01 0.7 0.19 0.54 C 158 CV099829 3 113.21 104.2 118.50.01 0.41 0.09 0.67 C 158 CV099829 4 166.31 161.3 179.5 0.01 0.36 0.080.65 C 158 CV099829 5 80.01 71.9 89.4 0.01 0.44 0.11 0.67 C 158 CV0998294 72.31 62.8 79.3 0.01 0.86 0.17 0.57 D 169 CV102084 2 107.51 100.5118.3 0.01 1.04 0.23 0.76 E 173 CV102084 2 115.6 107.5 119.6 0.01 0.510.08 0.52 E 173 CV102084 2 114.61 108.6 118.7 0.05 0.64 0.09 0.50 F 171CV102084 2 113.9 102.9 122.9 0.01 0.78 0.14 0.50 E 173 CV102084 4 174.31166.3 184.4 0.01 0.47 0.07 0.51 F 171 CV102084 4 172.8 165.8 183.4 0.010.51 0.07 0.51 F 171 CV102084 4 172.8 165.8 183.4 0.01 0.81 0.15 0.48 E173 CV102084 6 74.31 64.3 84.1 0.01 0.65 0.13 0.50 E 173 CV102084 678.31 65.3 85.3 0.01 0.93 0.19 0.52 G 111 CV095869 5 93.6 84.9 100.60.01 −0.58 0.23 0.49 H 156 CV097202 5 98.1 90.1 108.6 0.01 −0.65 0.20.38 I 158 CV103141 9 69.9 60.9 74.9 0.01 0.65 0.18 0.64 J 153 CV1058935 89.61 85.6 100.4 0.01 0.53 0.17 0.52 K 182 CV595358 5 90.3 86 93.20.01 1.43 0.12 0.92 K 182 CV595358 7 109.3 106.1 121.3 0.05 0.92 0.080.94 L 173 CV593417 5 90.3 85.1 98.8 0.01 1.97 0.67 0.88 M 174 CV5934175 90.3 80.6 95.6 0.01 1.7 0.51 0.69 O 142 CV117407 9 69.3 63.6 75.3 0.010.41 0.12 0.54 P 150 CV592505 4 165.8 161.2 171.9 0.01 0.45 0.13 0.54 Q146 CV592420 9 72.9 67.5 83.9 0.01 0.54 0.13 0.53 *p-value is based on1,000 permutation tests; ^(†) Based on Monsanto's internal consensusgenetic map.

Example 3. Identification of Molecular Markers Associated with NLBDisease Resistance Via Single-Marker Analysis (SMA)

Single-marker analysis (SMA) is performed to identify markers associatedwith NLB resistance using the genotypic data from Example 1. For eachmarker, the thresholds (p-value) for SMA are based on 10,000 randompermutation tests (Churchill and Doerg, Genetics, 138(3):963-71 (1994)).

In total, 126 SNP markers are identified to be linked to NLB diseaseresistance (Table 4). Table 4 also provides the effect estimates on NLBrating score for each marker linked to NLB disease resistance. Furtherprovided are the SEQ ID NO of the marker, chromosome position, markerposition on Monsanto's internal consensus genetic map, correspondingmarker position on the Neighbors 2008 maize genetic map (publiclyavailable at the MaizeGDB website, maizegdb.org/data_center/map),genetic source of favorable allele, resistant allele SNP, susceptibleallele SNP, the estimated effect that the marker polymorphism has on theNLB rating score, and p-value based on 10,000 random permutation tests.For example, SEQ ID NO: 1 is associated with a 0.47% reduction in NLBrating score by one copy of the resistant allele. However, one of skillin the art recognizes that a “resistant” allele at one locus can be a“susceptible” allele in a different genetic background. Thus, thisdisclosure is not limited to the “resistant” and “susceptible” allelesexemplified herein.

The primer sequences for amplifying exemplary SNP marker loci linked toNLB disease resistance and the probes used to genotype the correspondingSNP sequences are provided in Table 5. In an illustrative example, SNPmarker SEQ ID NO: 1 can be amplified using the primers described inTable 5 as SEQ ID NO: 90 (forward primer) and SEQ ID NO: 179 (reverseprimer), and detected with probes indicated as SEQ ID NO: 268 (Probe 1)and SEQ ID NO: 357 (Probe 2).

TABLE 4 Estimate effects of markers linked to NLB disease resistancefrom all mapping populations by SMA. MON IBM2008 Genetic SourceExemplary Exemplary Single Permutation SEQ Map Map of FavorableResistant Susceptible Allele Testing ID NO. Chromosome (cM) (IcM) AlleleAllele Allele Effect Probability 1 2 102.8 342.0 CV112894 A G 0.47 0.0012 2 105.6 347.4 CV102084 G C 0.44 0.001 3 2 106.5 370.8 CV112894 A G0.47 0.001 4 2 106.7 349.9 CV102084 A G 0.49 0.001 5 2 107.3 351.2CV102084 T C 0.43 0.001 6 2 108.3 353.5 CV102084 G A 0.60 0.001 7 2108.3 370.8 CV102084 T G 0.50 0.001 8 2 109.1 355.6 CV102084 A G 0.560.001 9 2 109.9 358.3 CV112894 T A 0.54 0.001 10 2 110.0 361.2 CV102084G A 0.62 0.001 11 2 111.4 370.0 CV102084 A C 0.41 0.001 12 2 113.2 374.0CV112894 A G 0.56 0.001 13 2 113.6 374.5 CV102084 G A 0.61 0.001 14 2117.3 380.7 CV102084 G A 0.83 0.001 15 2 117.4 380.8 CV102084 C T 0.370.001 16 2 120.2 388.9 CV102084 T C 0.56 0.001 17 2 120.7 390.5 CV102084A C 0.64 0.001 18 2 120.9 391.2 CV112894 C T 0.66 0.001 19 3 100.8 348.1CV117407 T C 0.57 0.001 19 3 100.8 348.1 CV099829 T C 0.57 0.001 20 3102.2 352.2 CV117407 G T 0.55 0.001 20 3 102.2 352.2 CV099829 G T 0.550.001 21 3 104.2 358.1 CV117407 G A 0.56 0.001 21 3 104.2 358.1 CV099829G A 0.56 0.001 22 3 110.9 382.6 CV117407 A G 0.58 0.001 22 3 110.9 382.6CV099829 A G 0.58 0.001 23 3 111.6 387.5 CV118913 G A 0.59 0.001 23 3111.6 387.5 CV095508 G A 0.59 0.001 24 3 112.2 390.8 CV117407 T C 0.580.001 24 3 112.2 390.8 CV099829 T C 0.58 0.001 25 3 114.9 398.4 CV095508C T 0.43 0.001 26 3 115.9 401.2 CV118913 T A 0.34 0.001 27 3 115.9 401.2CV095508 T C 0.43 0.001 28 3 116.5 403.0 CV117407 T C 0.46 0.001 28 3116.5 403.0 CV099829 T C 0.46 0.001 29 3 118.0 408.4 CV117407 C T 0.440.001 29 3 118.0 408.4 CV099829 C T 0.44 0.001 30 3 119.2 412.5 CV117407G A 0.44 0.001 30 3 119.2 412.5 CV099829 G A 0.44 0.001 31 3 123.4 429.3CV095508 T C 0.40 0.001 32 4 155.0 531.5 CV095508 A C 0.33 0.001 33 4162.8 573.4 CV099829 G A 0.30 0.001 34 4 164.3 576.6 CV102084 G A 0.530.001 35 4 165.2 578.4 CV102084 G A 0.61 0.001 36 4 165.4 578.8 CV102084A C 0.60 0.001 37 4 165.8 579.6 CV102084 A T 0.60 0.001 37 4 165.8 579.6CV102084 A T 0.60 0.001 37 4 165.8 579.6 CV102084 A T 0.60 0.001 38 4166.3 581.8 CV102084 G A 0.58 0.001 39 4 166.3 581.8 CV102084 T C 0.580.001 39 4 166.3 581.8 CV102084 T C 0.58 0.001 39 4 166.3 581.8 CV114258T C 0.58 0.001 40 4 167.2 583.8 CV095508 C T 0.32 0.001 41 4 168.4 586.4CV105893 G A 0.34 0.001 42 4 169.3 588.3 CV102084 T A 0.43 0.001 43 4170.5 590.9 CV102084 T A 0.44 0.001 44 4 171.9 594.0 CV102084 G T 0.640.001 45 4 172.8 601.6 CULU085 A G 0.49 0.001 46 4 173.3 601.4 CV102084T G 0.74 0.001 47 4 175.5 610.2 CV114258 C A 0.59 0.001 48 4 176.4 614.4CV102084 C T 0.61 0.001 48 4 176.4 614.4 CV102084 C T 0.61 0.001 48 4176.4 614.4 CV102084 C T 0.61 0.001 48 4 176.4 614.4 CV102084 C T 0.610.001 49 4 176.9 616.7 CV105893 A G 0.39 0.001 50 4 183.4 647.2 CV099829A T 0.34 0.001 50 4 183.4 647.2 CV105893 A T 0.34 0.001 51 4 185.2 655.6CV102084 A G 0.59 0.001 51 4 185.2 655.6 CV102084 A G 0.59 0.001 52 4185.7 656.5 CV102084 C T 0.52 0.001 52 4 185.7 656.5 CV102084 C T 0.520.001 52 4 185.7 656.5 CV102084 C T 0.52 0.001 53 5 83.7 295.8 CV097202C A 0.39 0.001 54 5 83.9 296.7 CV095869 T C 0.49 0.001 55 5 86.6 310.8CV097202 C G 0.47 0.001 55 5 86.6 310.8 CV105893 C G 0.47 0.001 56 587.2 313.9 CV097202 C T 0.38 0.001 57 5 89.0 321.3 CV097202 C A 0.400.001 58 5 89.7 321.3 CV105893 A G 0.56 0.001 59 5 93.2 325.0 CV105893 TC 0.55 0.001 60 5 93.6 328.5 CV095869 A C 0.58 0.001 61 5 96.7 333.8CV105893 A G 0.53 0.001 62 5 99.4 336.7 CV105893 T C 0.55 0.001 63 5102.6 340.0 CV097202 T C 0.41 0.001 64 5 103.3 342.5 CV105893 C T 0.540.001 65 5 105.2 347.6 CV095869 G T 0.41 0.001 66 6 63.9 302.0 CV102084G A 0.53 0.001 67 6 64.1 302.7 CV102084 C T 0.48 0.001 68 6 64.2 303.1CV102084 T C 0.53 0.001 69 6 64.2 303.1 CV102084 G T 0.50 0.001 70 664.5 304.1 CV102084 T G 0.50 0.001 71 6 65.3 306.9 CV102084 T A 0.480.001 72 6 66.0 312.3 CV102084 G A 0.45 0.001 73 6 66.4 313.4 CV102084 GA 0.45 0.001 74 6 68.1 318.2 CV102084 T C 0.51 0.001 75 6 68.1 318.2CV102084 C T 0.52 0.001 76 6 68.3 318.7 CV102084 C G 0.46 0.001 77 670.0 324.0 CV102084 G A 0.48 0.001 78 6 71.3 329.9 CV102084 T C 0.460.001 79 6 73.2 337.5 CV102084 A T 0.36 0.001 80 6 74.3 341.9 CV102084 AG 0.50 0.001 81 6 74.7 343.2 CV102084 A G 0.26 0.001 82 6 77.7 350.2CV102084 T C 0.35 0.001 83 6 83.8 369.0 CV102084 C T 0.36 0.001 84 685.0 373.8 CV102084 G A 0.31 0.001 85 9 58.1 164.3 CV103141 T C 0.270.001 86 9 61.4 188.5 CV103141 C T 0.30 0.001 87 9 63.3 199.4 CV103141 CT 0.46 0.001 88 9 68.6 227.2 CV103141 G C 0.46 0.001 89 9 69.9 240.5CV103141 A G 0.38 0.001 446 5 80.0 282.6 CV595358 T C 1.64 0.001 447 580.0 282.6 CV595358 T G 1.64 0.001 448 5 80.3 283.9 CV595358 C T 1.650.001 449 5 80.6 286.7 CV595358 T C 1.65 0.001 450 5 80.6 286.7 CV595358C T 1.65 0.001 451 5 82.4 291.2 CV595358 G A 1.82 0.001 53 5 83.7 295.8CV595358 A C 1.66 0.001 452 5 84.0 297.1 CV595358 G A 1.88 0.001 453 584.1 297.5 CV595358 A C 1.88 0.001 454 5 85.9 306.9 CV595358 T C 1.880.001 455 5 86.0 307.3 CV595358 T C 1.88 0.001 456 5 86.0 307.3 CV595358C T 1.88 0.001 457 5 88.4 311.8 CV595358 G A 2.00 0.001 57 5 89.0 321.3CV595358 A C 1.93 0.001 458 5 89.2 310.4 CV595358 G T 1.93 0.001 459 590.3 316.9 CV595358 T C 2.00 0.001 460 5 90.3 316.9 CV595358 G C 2.000.001 461 5 90.8 320.6 CV595358 G A 2.00 0.001 462 5 91.4 321.9 CV595358A G 1.93 0.001 463 5 92.0 322.9 CV595358 G C 1.93 0.001 59 5 93.2 327.6CV595358 C T 1.93 0.001 464 5 93.6 328.5 CV595358 T C 1.87 0.001 465 595.3 332.3 CV595358 G T 1.87 0.001 466 5 97.8 335.0 CV595358 C A 1.790.001 62 5 99.4 336.7 CV595358 T C 1.79 0.001 467 5 101.8 339.3 CV595358A G 1.80 0.001 446 5 80.0 282.6 CV593417 T C 1.83 0.001 447 5 80.0 282.6CV593417 T G 1.83 0.001 448 5 80.3 283.9 CV593417 C T 1.83 0.001 449 580.6 286.7 CV593417 T C 1.83 0.001 450 5 80.6 286.7 CV593417 C T 1.830.001 451 5 82.4 291.2 CV593417 G A 1.83 0.001 53 5 83.7 295.8 CV593417A C 1.83 0.001 452 5 84.0 297.1 CV593417 G A 1.87 0.001 453 5 84.1 297.5CV593417 A C 1.87 0.001 454 5 85.9 306.9 CV593417 T C 1.91 0.001 455 586.0 403.0 CV593417 T C 1.91 0.001 456 5 86.0 403.0 CV593417 C T 1.910.001 457 5 88.4 311.8 CV593417 G A 1.93 0.001 57 5 89.0 321.3 CV593417A C 1.91 0.001 458 5 89.2 310.4 CV593417 G T 1.91 0.001 459 5 90.3 316.9CV593417 T C 1.93 0.001 460 5 90.3 316.9 CV593417 G C 1.93 0.001 461 590.8 320.6 CV593417 G A 1.94 0.001 462 5 91.4 321.9 CV593417 A G 1.920.001 463 5 92.0 322.9 CV593417 G C 1.92 0.001 464 5 93.6 328.5 CV593417T C 1.92 0.001 466 5 97.8 335.0 CV593417 C A 1.87 0.001 467 5 101.8339.3 CV593417 A G 1.72 0.001 468 5 102.3 340.3 CV593417 C A 1.68 0.00164 5 103.3 342.5 CV593417 T C 1.61 0.001 446 5 80.0 282.6 CV593417 T C1.61 0.001 448 5 80.3 283.9 CV593417 C T 1.61 0.001 449 5 80.6 286.7CV593417 T C 1.61 0.001 450 5 80.6 286.7 CV593417 C T 1.61 0.001 451 582.4 291.2 CV593417 G A 1.62 0.001 409 5 83.7 295.8 CV593417 A C 1.620.001 452 5 84.0 297.1 CV593417 G A 1.70 0.001 453 5 84.1 297.5 CV593417A C 1.70 0.001 454 5 85.9 306.9 CV593417 T C 1.68 0.001 455 5 86.0 307.3CV593417 T C 1.68 0.001 456 5 86.0 307.3 CV593417 C T 1.68 0.001 457 588.4 311.8 CV593417 G A 1.67 0.001 57 5 89.0 321.3 CV593417 A C 1.670.001 458 5 89.2 310.4 CV593417 G T 1.67 0.001 459 5 90.3 316.9 CV593417T C 1.67 0.001 460 5 90.3 316.9 CV593417 G C 1.67 0.001 462 5 91.4 321.9CV593417 A G 1.62 0.001 463 5 92.0 322.9 CV593417 G C 1.59 0.001 464 593.6 328.5 CV593417 T C 1.45 0.001 466 5 97.8 335.0 CV593417 C A 1.250.001 467 5 101.8 339.3 CV593417 A G 1.03 0.001 469 7 103.3 381.2CV595358 T C 1.03 0.001 470 7 110.0 409.4 CV595358 G A 1.45 0.001 471 4159.2 564.4 CV592505 G A 0.25 0.001 472 4 161.4 570.3 CV592505 T C 0.280.001 473 4 163.7 575.4 CV592505 G C 0.35 0.001 474 4 165.8 579.6CV592505 G T 0.39 0.001 40 4 167.2 583.8 CV592505 C T 0.40 0.001 475 4170.1 590.1 CV592505 A G 0.30 0.001 44 4 171.9 594.0 CV592505 T G 0.290.001 47 4 175.5 610.2 CV592505 C A 0.13 0.001 476 9 61.6 325.0 CV117407G A 0.18 0.001 477 9 69.3 232.8 CV117407 C T 0.34 0.001 478 9 79.2 295.7CV117407 G A 0.22 0.001 479 9 61.5 189.3 CV592420 C G 0.44 0.001 480 967.6 340.0 CV592420 C G 0.54 0.001 481 9 70.4 243.6 CV592420 A G 0.500.001 482 9 72.9 254.5 CV592420 C T 0.56 0.001 cM = centimorgans, IcM =map units of the IBM2 2008 Neighbors Genetic Map.In Table 4, “IcM” refers to the map units of the IBM2 2008 NeighborsGenetic Map, which was generated with an intermated recombinant inbredpopulation (syn 4) that resulted in approximately a four-fold increasein the number of meiosies as compared to the typical recombinationexperiment that is used to generate cM distances (Lee et al., 2002,Plant Mol Biol 48:453 and the Maize Genetics and Genomics Database).“cM” refers to the classical definition of a centimorgan wherein one cMis equal to a 1% chance that a trait at one genetic locus will beseparated from a trait at another locus due to crossing over in a singlegeneration (meaning the traits co-segregate 99% of the time duringmeiosis), and this definition is used herein to delineate map locationspertaining to this invention.

TABLE 5 Exemplary primers and probes used for genotyping representativeSNP markers associated with NLB disease resistance. SEQ ID NO. SEQ SNPForward Reverse Probe Probe ID NO. Position Primer Primer 1 2 1 101 90179 268 357 2 101 91 180 269 358 3 101 92 181 270 359 4 77 93 182 271360 5 101 94 183 272 361 6 136 95 184 273 362 7 104 96 185 274 363 8 11297 186 275 364 9 902 98 187 276 365 10 101 99 188 277 366 11 205 100 189278 367 12 245 101 190 279 368 13 43 102 191 280 369 14 144 103 192 281370 15 101 104 193 282 371 16 247 105 194 283 372 17 341 106 195 284 37318 91 107 196 285 374 19 216 108 197 286 375 20 81 109 198 287 376 21194 110 199 288 377 22 46 111 200 289 378 23 859 112 201 290 379 24 200113 202 291 380 25 73 114 203 292 381 26 352 115 204 293 382 27 162 116205 294 383 28 106 117 206 295 384 29 319 118 207 296 385 30 127 119 208297 386 31 101 120 209 298 387 33 319 122 211 300 389 35 101 124 213 302391 36 373 125 214 303 392 37 115 126 215 304 393 38 171 127 216 305 39439 37 128 217 306 395 40 101 129 218 307 396 41 101 130 219 308 397 42101 131 220 309 398 43 101 132 221 310 399 44 2239 133 222 311 400 45569 134 223 312 401 46 101 135 224 313 402 47 240 136 225 314 403 48 247137 226 315 404 49 719 138 227 316 405 50 429 139 228 317 406 51 101 140229 318 407 52 81 141 230 319 408 53 62 142 231 320 409 54 167 143 232321 410 55 99 144 233 322 411 56 390 145 234 323 412 57 279 146 235 324413 58 101 147 236 325 414 59 61 148 237 326 415 60 339 149 238 327 41661 125 150 239 328 417 62 101 151 240 329 418 63 369 152 241 330 419 64101 153 242 331 420 65 101 154 243 332 421 66 101 155 244 333 422 67 101156 245 334 423 68 101 157 246 335 424 69 101 158 247 336 425 71 101 160249 338 427 72 279 161 250 339 428 73 265 162 251 340 429 74 101 163 252341 430 75 101 164 253 342 431 76 209 165 254 343 432 77 256 166 255 344433 78 101 167 256 345 434 79 101 168 257 346 435 80 91 169 258 347 43681 47 170 259 348 437 82 321 171 260 349 438 83 101 172 261 350 439 84474 173 262 351 440 85 101 174 263 352 441 86 101 175 264 353 442 87 101176 265 354 443 88 49 177 266 355 444 89 223 178 267 356 445 446 101 483520 557 594 447 101 484 521 558 595 448 216 485 522 559 596 449 184 486523 560 597 450 101 487 524 561 598 451 101 488 525 562 599 452 265 489526 563 600 453 101 490 527 564 601 454 105 491 528 565 602 455 254 492529 566 603 456 322 493 530 567 604 457 345 494 531 568 605 458 58 495532 569 606 459 342 496 533 570 607 460 542 497 534 571 608 461 101 498535 572 609 462 73 499 536 573 610 463 129 500 537 574 611 464 101 501538 575 612 465 101 502 539 576 613 466 234 503 540 577 614 467 101 504541 578 615 468 486 505 542 579 616 469 191 506 543 580 617 470 426 507544 581 618 471 173 508 545 582 619 472 101 509 546 583 620 473 101 510547 584 621 474 101 511 548 585 622 475 101 512 549 586 623 476 101 513550 587 624 477 101 514 551 588 625 478 412 515 552 589 626 479 444 516553 590 627 480 101 517 554 591 628 481 101 518 555 592 629 482 101 519556 593 630

One of skill in the art recognizes that sequences to either side of thegiven primers can be used in place of the given primers, so long as theprimers can amplify a region that includes the allele to be detected.The precise probe used for detection can vary, e.g., any probe that canidentify the region of a marker amplicon to be detected can besubstituted for those probes exemplified herein. Configuration of theamplification primers and detection probes can also be varied. Thus,this disclosure is not limited to the primers, probes, or markersequences specifically listed in the tables.

In summary, the QTLs are designated as NLB_2.01, NLB_3.01, NLB_4.01,NLB_4.02, NLB_5.01, NLB_6.01, NLB_7.01, and NLB_9.01 (Table 6).

TABLE 6 Summary of NLB QTLs. Interval of QTL Peak QTL Chromosome MON Map(cM) IBM2008 Map (IcM) Designation 2 114-117 375-380 NLB_2.01 3 109-114370-396 NLB_3.01 4 166-169 580-588 NLB_4.01 4 172-177 594-617 NLB_4.02 589-98 321-335 NLB_5.01 6 73-75 336-344 NLB_6.01 7 109 405 NLB_7.01 963-73 196-255 NLB_9.01 cM = centimorgans; IcM = map units of the IBM22008 Neighbors Genetic Map.

Example 4. Validation of NLB QTLs

Plants with or without resistant NLB QTL are derived. Plants carryingthe resistant allele of NLB-2.01, NLB-3.01 or NLB-4.02 show significantreductions in NLB rating score when compared to plants carrying thesusceptible allele (Table 7).

TABLE 7 Validation of NLB QTLs. NLB QTL Resistance Infection p- intervalQTL Profile Score value NLB_2.01 Absent 5.88 2.74E−58 Present 2.47NLB_3.01 Absent 5.3 1.70E−37 Present 3.5 NLB_4.02 Absent 5.34 7.23E−27Present 2.92 NLB_6.01 Absent 3.78 0.15 Present 4.26

Example 5: Introgression of NLB Resistance QTLs into Additional MaizeLines

A maize plant comprising one or more, two or more, or three or more NLBresistance QTLs is crossed with an elite maize line comprising adesirable trait (e.g., improved yield under water, temperature, or peststress conditions), but susceptible to NLB. F₁ progeny plants from thiscross are assayed for one or more SNP markers exemplified in Tables 4and 5 or molecular markers linked to those SNP markers to select for NLBresistance QTLs. A selected F₁ progeny plant is then backcrossed withthe parent elite maize line comprising the desirable trait (recurrentparent). Plants from the BC1 generation are also genotyped using SNPmarkers exemplified in Table 5, or a linked marker, to select for NLBresistance QTLs. After multiple rounds of backcrossing (e.g., 5-7generations) with the recurrent parent line, a new elite maize line isobtained comprising both NLB resistance and the desirable trait in therecurrent parent line. Using the above introgression and marker-assistedselection strategy, the pyramiding or stacking of multiple NLBresistance QTLs can be achieved.

As various modifications could be made in the constructions and methodsherein described and illustrated without departing from the scope ofthis disclosure, it is intended that the foregoing description shall beinterpreted as illustrative rather than limiting. The breadth and scopeof the present disclosure should not be limited by any of theabove-described exemplary embodiments, but should be defined only inaccordance with the following claims appended hereto and theirequivalents. All patent and non-patent documents cited in thisspecification are incorporated herein by reference in their entireties.

1-26. (canceled)
 27. A method of creating a population of Northern LeafBlight (NLB) resistant corn plants, corn seeds, or corn cells, saidmethod comprising: a) crossing a first NLB resistant corn plantcomprising NLB resistance quantitative trait locus (QTL) NLB_4.02 with asecond corn plant to generate a first population of corn plants, cornseeds, or corn cells; b) genotyping said first population of cornplants, corn seeds, or corn cells at one or more marker loci linked to,and within 10 centimorgans (cM) of, said NLB resistance QTL NLB_4.02;and c) selecting from said first population one or more corn plants,corn seeds, or corn cells having resistance to NLB comprising said oneor more of said marker loci linked to said NLB resistance QTL NLB_4.02linked to an NLB resistance allele selected from the group consistingof: SEQ ID NO: 33 comprising a G, at position number 319; SEQ ID NO: 35comprising a G, at position number 101; SEQ ID NO: 36 comprising an A,at position number 373; SEQ ID NO: 37 comprising an A, at positionnumber 115; SEQ ID NO: 38 comprising a G, at position number 171; SEQ IDNO: 39 comprising a T, at position number 37; SEQ ID NO: 40 comprising aC, at position number 101; SEQ ID NO: 41 comprising a G, at positionnumber 101; SEQ ID NO: 42 comprising a T, at position number 101; SEQ IDNO: 43 comprising a T, at position number 101; SEQ ID NO: 44 comprisinga G or a T, at position number 2239; SEQ ID NO: 45 comprising an A, atposition number 569; SEQ ID NO: 46 comprising a T, at position number101; SEQ ID NO: 47 comprising a C, at position number 240; SEQ ID NO: 48comprising a C, at position number 247; SEQ ID NO: 49 comprising an A,at position number 719; SEQ ID NO: 50 comprising an A, at positionnumber 429; SEQ ID NO: 51 comprising an A, at position number 101; SEQID NO: 52 comprising a C, at position number 81; SEQ ID NO: 471comprising a G, at position number 173; SEQ ID NO: 472 comprising a T,at position number 101; SEQ ID NO: 473 comprising a G, at positionnumber 101; SEQ ID NO: 474 comprising a G, at position number 101; andSEQ ID NO: 475 comprising an A, at position number
 101. 28. The methodof claim 27, wherein said selecting comprises selecting one or moremarker loci located in a chromosomal interval flanked by any two of SEQID NOs: 32 to 52 and 471 to 475, and said NLB resistance allele is atsaid QTL NLB_4.02.
 29. The method of claim 27, wherein said selectingcomprises selecting one or more marker loci are located in a chromosomalinterval flanked by any two of SEQ ID NOs: 33 to 42, 473 and 474, andsaid NLB resistance allele is at said QTL NLB_4.02.
 30. The method ofclaim 27, wherein said selecting comprises selecting one or more markerloci are located in a chromosomal interval flanked by any two of SEQ IDNOs: 43 to 49, and said NLB resistance allele is at said QTL NLB_4.02.31. The method of claim 27, wherein said selecting comprises selectingone or more marker loci are linked to, and within 5 cM of, any one ofthe marker loci selected from the group consisting of SEQ ID NOs: SEQ IDNOs: 32 to 52 and 471 to 475, and said NLB resistance allele is at saidQTL NLB_4.02.
 32. The method of claim 27, wherein said selected plantcomprises NLB resistance QTL NLB_4.02 and mild resistance or resistanceto infection by Exserohilum turcicum.
 33. The method of claim 27,wherein said selected one or more corn plants exhibits reduced root rot,reduced stalk rot, fewer leaf lesions, less foliage destruction, or anycombination thereof, compared to corn plants lacking said NLB resistanceQTL NLB_4.02 when grown under a high NLB stress condition.
 34. Themethod of claim 27, wherein said NLB resistance QTL NLB_4.02 does notconfer a yield penalty when grown under a low NLB stress condition.] 35.The method of claim 27, wherein said method further comprises: producingfrom said one or more corn plants, corn seeds, or corn cells selected instep c) a second population of corn plants, corn seeds, or corn cellscomprising said NLB resistance QTL NLB_4.02.
 36. The method of claim 35,wherein said second population of corn plants or seeds exhibits areduction of NLB rating score of 1 or more as compared to corn plants orseeds lacking said NLB resistance QTL NLB_4.02 when grown under a highNLB stress condition.
 37. The method of claim 35, wherein said secondpopulation of corn plants or seeds exhibits a reduction of NLB ratingscore of 2 or more as compared to corn plants or seeds lacking said NLBresistance QTL NLB_4.02 when grown under a high NLB stress condition.38. The method of claim 27, wherein said one or more marker loci areselected from the group consisting of: SEQ ID NO: 33 comprising a G, atposition number 319; SEQ ID NO: 35 comprising a G, at position number101; SEQ ID NO: 36 comprising an A, at position number 373; SEQ ID NO:37 comprising an A, at position number 115; SEQ ID NO: 38 comprising aG, at position number 171; SEQ ID NO: 39 comprising a T, at positionnumber 37; SEQ ID NO: 40 comprising a C, at position number 101; SEQ IDNO: 41 comprising a G, at position number 101; SEQ ID NO: 42 comprisinga T, at position number 101; SEQ ID NO: 43 comprising a T, at positionnumber 101; SEQ ID NO: 44 comprising a G or a T, at position number2239; SEQ ID NO: 45 comprising an A, at position number 569; SEQ ID NO:46 comprising a T, at position number 101; SEQ ID NO: 47 comprising a C,at position number 240; SEQ ID NO: 48 comprising a C, at position number247; SEQ ID NO: 49 comprising an A, at position number 719; SEQ ID NO:50 comprising an A, at position number 429; SEQ ID NO: 51 comprising anA, at position number 101; SEQ ID NO: 52 comprising a C, at positionnumber 81; SEQ ID NO: 471 comprising a G, at position number 173; SEQ IDNO: 472 comprising a T, at position number 101; SEQ ID NO: 473comprising a G, at position number 101; SEQ ID NO: 474 comprising a G,at position number 101; and SEQ ID NO: 475 comprising an A, at positionnumber
 101. 39. The method of claim 27, wherein said selecting comprisesselecting one or more corn plants, corn seeds, or corn cells that do notcomprise NLB resistance quantitative trait loci (QTL) NLB_4.01.
 40. Themethod of claim 27, further comprising selecting one or more cornplants, corn seeds, or corn cells comprising NLB resistance quantitativetrait loci (QTL) NLB_4.01.
 41. A method of creating a population ofNorthern Leaf Blight (NLB) resistant corn plants, corn seeds, or corncells, said method comprising: a) crossing a first NLB resistant cornplant comprising an NLB resistance quantitative trait loci (QTL)NLB_4.02 with a second corn plant to generate a first population of cornplants, corn seeds, or corn cells; b) genotyping said first populationof corn plants, corn seeds, or corn cells at one or more marker locilinked to, and within 10 centimorgans (cM) of, any one of the markerloci selected from the group consisting of SEQ ID NOs: 32 to 52 and 471to 475, wherein said marker is associated with said NLB resistance QTLNLB_4.02; and c) selecting from said first population one or more cornplants, corn seeds, or corn cells having resistance to NLB comprisingsaid one or more of said marker loci linked to said NLB resistance QTLNLB_4.02 linked to an NLB resistance allele selected from the groupconsisting of: SEQ ID NO: 33 comprising a G, at position number 319; SEQID NO: 35 comprising a G, at position number 101; SEQ ID NO: 36comprising an A, at position number 373; SEQ ID NO: 37 comprising an A,at position number 115; SEQ ID NO: 38 comprising a G, at position number171; SEQ ID NO: 39 comprising a T, at position number 37; SEQ ID NO: 40comprising a C, at position number 101; SEQ ID NO: 41 comprising a G, atposition number 101; SEQ ID NO: 42 comprising a T, at position number101; SEQ ID NO: 43 comprising a T, at position number 101; SEQ ID NO: 44comprising a G or a T, at position number 2239; SEQ ID NO: 45 comprisingan A, at position number 569; SEQ ID NO: 46 comprising a T, at positionnumber 101; SEQ ID NO: 47 comprising a C, at position number 240; SEQ IDNO: 48 comprising a C, at position number 247; SEQ ID NO: 49 comprisingan A, at position number 719; SEQ ID NO: 50 comprising an A, at positionnumber 429; SEQ ID NO: 51 comprising an A, at position number 101; SEQID NO: 52 comprising a C, at position number 81; SEQ ID NO: 471comprising a G, at position number 173; SEQ ID NO: 472 comprising a T,at position number 101; SEQ ID NO: 473 comprising a G, at positionnumber 101; SEQ ID NO: 474 comprising a G, at position number 101; andSEQ ID NO: 475 comprising an A, at position number
 101. 42. The methodof claim 27, wherein said selecting comprises selecting a first orsecond corn plant comprises an NLB resistance QTL selected fromNLB_2.01, NLB_3.01, NLB_6.01, NLB_7.01, or NLB_9.01, wherein said NLBresistance QTL is linked to a second NLB resistance allele from thegroup consisting of: SEQ ID NO: 1 comprising an A, at position number101; SEQ ID NO: 2 comprising a G, at position number 101; SEQ ID NO: 3comprising an A, at position number 101; SEQ ID NO: 4 comprising an A,at position number 77; SEQ ID NO: 5 comprising a T, at position number101; SEQ ID NO: 6 comprising a G, at position number 136; SEQ ID NO: 7comprising a T, at position number 104; SEQ ID NO: 8 comprising an A, atposition number 112; SEQ ID NO: 9 comprising a T, at position number902; SEQ ID NO: 10 comprising a G, at position number 101; SEQ ID NO: 11comprising an A, at position number 205; SEQ ID NO: 12 comprising an A,at position number 245; SEQ ID NO: 13 comprising a G, at position number43; SEQ ID NO: 14 comprising a G, at position number 144; SEQ ID NO: 15comprising a C, at position number 101; SEQ ID NO: 16 comprising a T, atposition number 247; SEQ ID NO: 17 comprising an A, at position number341; SEQ ID NO: 18 comprising a C, at position number 91; SEQ ID NO: 19comprising a T, at position number 216; SEQ ID NO: 20 comprising a G, atposition number 81; SEQ ID NO: 21 comprising a G, at position number194; SEQ ID NO: 22 comprising an A, at position number 46; SEQ ID NO: 23comprising a G, at position number 859; SEQ ID NO: 24 comprising a T, atposition number 200; SEQ ID NO: 25 comprising a C, at position number73; SEQ ID NO: 26 comprising a T, at position number 352; SEQ ID NO: 27comprising a T, at position number 162; SEQ ID NO: 28 comprising a T, atposition number 106; SEQ ID NO: 29 comprising a C, at position number319; SEQ ID NO: 30 comprising a G, at position number 127; SEQ ID NO: 31comprising a T, at position number 101; SEQ ID NO: 65 comprising a G, atposition number 101; SEQ ID NO: 67 comprising a C, at position number101; SEQ ID NO: 68 comprising a T, at position number 101; SEQ ID NO: 69comprising a G, at position number 101; SEQ ID NO: 70 comprising a T, atposition number 101; SEQ ID NO: 71 comprising a T, at position number101; SEQ ID NO: 72 comprising a G, at position number 279; SEQ ID NO: 73comprising a G, at position number 265; SEQ ID NO: 74 comprising a T, atposition number 101; SEQ ID NO: 75 comprising a C, at position number101; SEQ ID NO: 76 comprising a C, at position number 209; SEQ ID NO: 77comprising a G, at position number 256; SEQ ID NO: 78 comprising a T, atposition number 101; SEQ ID NO: 79 comprising an A, at position number101; SEQ ID NO: 80 comprising an A, at position number 91; SEQ ID NO: 81comprising an A, at position number 47; SEQ ID NO: 82 comprising a T, atposition number 321; SEQ ID NO: 83 comprising a C, at position number101; SEQ ID NO: 84 comprising a G, at position number 474; SEQ ID NO: 85comprising a T, at position number 101; SEQ ID NO: 86 comprising a C, atposition number 101; SEQ ID NO: 87 comprising a C, at position number101; SEQ ID NO: 88 comprising a G, at position number 49; SEQ ID NO: 89comprising an A, at position number 223; SEQ ID NO: 469 comprising a T,at position number 191; SEQ ID NO: 470 comprising a G, at positionnumber 426; SEQ ID NO: 476 comprising a G, at position number 101; SEQID NO: 477 comprising a C, at position number 101; SEQ ID NO: 478comprising a G, at position number 412; SEQ ID NO: 479 comprising a C,at position number 444; SEQ ID NO: 480 comprising a C, at positionnumber 101; SEQ ID NO: 481 comprising an A, at position number 101; andSEQ ID NO: 482 comprising a C, at position number
 101. 43. The method ofclaim 27, wherein said selecting comprises selecting a first or secondcorn plant comprises an NLB resistance QTL selected from NLB_2.01,NLB_3.01, NLB_6.01, NLB_7.01, or NLB_9.01, wherein said NLB resistanceQTL is linked to a second NLB resistance allele from the groupconsisting of: SEQ ID NO: 1 comprising an A, at position number 101; SEQID NO: 2 comprising a G, at position number 101; SEQ ID NO: 3 comprisingan A, at position number 101; SEQ ID NO: 4 comprising an A, at positionnumber 77; SEQ ID NO: 5 comprising a T, at position number 101; SEQ IDNO: 6 comprising a G, at position number 136; SEQ ID NO: 7 comprising aT, at position number 104; SEQ ID NO: 8 comprising an A, at positionnumber 112; SEQ ID NO: 9 comprising a T, at position number 902; SEQ IDNO: 10 comprising a G, at position number 101; SEQ ID NO: 11 comprisingan A, at position number 205; SEQ ID NO: 12 comprising an A, at positionnumber 245; SEQ ID NO: 13 comprising a G, at position number 43; SEQ IDNO: 14 comprising a G, at position number 144; SEQ ID NO: 15 comprisinga C, at position number 101; SEQ ID NO: 16 comprising a T, at positionnumber 247; SEQ ID NO: 17 comprising an A, at position number 341; SEQID NO: 18 comprising a C, at position number 91; SEQ ID NO: 19comprising a T, at position number 216; SEQ ID NO: 20 comprising a G, atposition number 81; SEQ ID NO: 21 comprising a G, at position number194; SEQ ID NO: 22 comprising an A, at position number 46; SEQ ID NO: 23comprising a G, at position number 859; SEQ ID NO: 24 comprising a T, atposition number 200; SEQ ID NO: 25 comprising a C, at position number73; SEQ ID NO: 26 comprising a T, at position number 352; SEQ ID NO: 27comprising a T, at position number 162; SEQ ID NO: 28 comprising a T, atposition number 106; SEQ ID NO: 29 comprising a C, at position number319; SEQ ID NO: 30 comprising a G, at position number 127; SEQ ID NO: 31comprising a T, at position number 101; SEQ ID NO: 65 comprising a G, atposition number 101; SEQ ID NO: 67 comprising a C, at position number101; SEQ ID NO: 68 comprising a T, at position number 101; SEQ ID NO: 69comprising a G, at position number 101; SEQ ID NO: 70 comprising a T, atposition number 101; SEQ ID NO: 71 comprising a T, at position number101; SEQ ID NO: 72 comprising a G, at position number 279; SEQ ID NO: 73comprising a G, at position number 265; SEQ ID NO: 74 comprising a T, atposition number 101; SEQ ID NO: 75 comprising a C, at position number101; SEQ ID NO: 76 comprising a C, at position number 209; SEQ ID NO: 77comprising a G, at position number 256; SEQ ID NO: 78 comprising a T, atposition number 101; SEQ ID NO: 79 comprising an A, at position number101; SEQ ID NO: 80 comprising an A, at position number 91; SEQ ID NO: 81comprising an A, at position number 47; SEQ ID NO: 82 comprising a T, atposition number 321; SEQ ID NO: 83 comprising a C, at position number101; SEQ ID NO: 84 comprising a G, at position number 474; SEQ ID NO: 85comprising a T, at position number 101; SEQ ID NO: 86 comprising a C, atposition number 101; SEQ ID NO: 87 comprising a C, at position number101; SEQ ID NO: 88 comprising a G, at position number 49; SEQ ID NO: 89comprising an A, at position number 223; SEQ ID NO: 469 comprising a T,at position number 191; SEQ ID NO: 470 comprising a G, at positionnumber 426; SEQ ID NO: 476 comprising a G, at position number 101; SEQID NO: 477 comprising a C, at position number 101; SEQ ID NO: 478comprising a G, at position number 412; SEQ ID NO: 479 comprising a C,at position number 444; SEQ ID NO: 480 comprising a C, at positionnumber 101; SEQ ID NO: 481 comprising an A, at position number 101; andSEQ ID NO: 482 comprising a C, at position number
 101. 44. The method ofclaim 42, wherein said NLB resistance QTL is NLB_2.01.
 45. The method ofclaim 42, wherein said NLB resistance QTL is NLB_3.01.
 46. The method ofclaim 42, wherein said NLB resistance QTL is NLB_6.01.
 47. The method ofclaim 42, wherein said NLB resistance QTL is NLB_7.01.
 48. The method ofclaim 42, wherein said NLB resistance QTL is NLB_9.01.
 49. The method ofclaim 43, wherein said NLB resistance QTL is NLB_2.01.
 50. The method ofclaim 43, wherein said NLB resistance QTL is NLB_3.01.
 51. The method ofclaim 43, wherein said NLB resistance QTL is NLB_6.01.
 52. The method ofclaim 43, wherein said NLB resistance QTL is NLB_7.01.
 53. The method ofclaim 43, wherein said NLB resistance QTL is NLB_9.01.